Dan Margulis Applied Color Theory
Camera Raw Settings
Camera Raw Settings
Posted by: "John Arnold"
Fri Feb 2, 2007 3:27 am (PST)
Hi,
On page 385 figure 16.4 of PP5E, Dan shows an image
that he describes as a "natural" open in Camera Raw. I believe
that by "natural open" Dan means with all of the "auto"
boxes unchecked and with the curve set to linear.
So I unchecked all auto boxes and saved the unadjusted
image. I then proceeded to set the LAB curves as Dan describes in the book.
When I set the curves in the Lightness channel, I blew the highlights in
the image out. So I went back into Camera Raw and noticed that even though
the Brightness setting was unchecked, the brightness was set to 50 by
default. When I set brightness to zero and then applied Dan's curves to the
Lightness channel, the image looked fine. So I assume that Dan's image had
the brightness set to zero as well.
So, here's my question. When using Camera Raw, should
you change the default for Brightness to zero or leave it at the default
value of 50? I always assumed that the Brightness setting was set to
default at 50 because it represented a neutral uncorrected brightness
setting, kind of like leaving the middle levels setting in Photoshop set to
zero. Is that correct or is zero the neutral Brightness setting?
Thank you for your help?
John Arnold
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Re: Camera Raw Settings
Posted by: "Wai-hong Chung"
Fri Feb 2, 2007 7:20 am (PST)
Hi All,
May I also ask that to get the most original capture,
should I do the following Camera Raw settings :-
White balance = As shoot; Exposure = 0; Shadows = 0 ;
Brightness = 0; Contrast = 0; Saturation = 0; Cutrve = linear ?
Thank you in advance !
Wai-hong Chung from Hong Kong
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Re: Camera Raw Settings
Posted by: "Mark Segal"
Fri Feb 2, 2007 7:22 am (PST)
I'm working exclusively with the new Camera Raw in CS3
Beta because it has vastly expanded capability compared with Camera Raw in
CS2, hence what I say here applies to CS3 in particular, but may be
generally valid. Brightness can range between -/+150. As you adjust, it
shifts mid-tone values in a non-linear manner much like the grey input
slider in Levels. The default setting of 50 is Adobe's guess about a
setting that would be a liveable starting point for image correction in
Camera Raw. It means nothing more than that, and in particular there is no
such thing as "neutral" when it comes to Brightness. I generally
find it one of the least useful correction tools in Camera Raw and hardly
ever use it - especially since Curves became part of the Camera Raw arsenal
with CS2, and all the more so with the Parametric and Point Curves options
in the new Camera Raw CS3 Beta. I have no idea where Dan started from in
the image to which you refer - I'm merely making the point that
"default" settings should be treated as starting points and they
are only as useful as the images require.
Mark Segal
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Re: Camera Raw Settings
Posted by: "MARK SEGAL"
Fri Feb 2, 2007 8:15 am (PST)
Wai-Hong,
Let's start with the approach - what are you trying to
do - what the camera saw and what you want it to have seen can be and often
are two different things. So Camera Raw is one tool in the arsenal for
making the image look like what you want it to look like. If you accept
that, it follows there is nothing religious about the original raw capture
itself except that you want to have set the exposure to maximize the amount
of information without clipping. Then it follows from that there is nothing
religious about the default Camera Raw settings - it is all a matter of
your approach and what is the most convenient starting point for image
correction. For example, in my case I set my defaults as you have them
below except Brightness is 50 and Contrast 25 only because they are
workable starting points for most images. I then generally leave these
alone and use Parametric and Point Curves, Recovery and Shadows (CS3 Beta)
for dealing with contrast and luminosity issues. I like
starting the life of the Curve at Linear like you
suggest below, simply because I don't want or need Adobe's suggestions
about initial image contrast. CS3 Beta has tons of stuff for colour
adjustment - the Vibrance slider in the first tab plus multiple options in
the H tab being the most interesting.
Mark Segal
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Camera Raw Settings
Posted by: "Andrew Rodney"
Fri Feb 2, 2007 8:17 am (PST)
The Brightness setting in ACR (and LR) is not what
you©ˆd think of when you think of Brightness in terms of
Photoshop. This is due to the linear nature of raw data where half is in
contained in the first stop of highlight data and due to the design. You
want to set either end of the tone using the Exposure and Black sliders
(use the option/alt key when sliding). New in ACR that you will not see in
Dan©ˆs book is Fill light and Recovery. You should do ALL
corrections in ACR from top down, left to right! Set Exposure, Recovery
(for highlights), then Fill light and then Blacks. Brightness is a minor
tweak that produces an S shapped curve OVER the above edits due to the
editing order. The Œdefault©ˆ is 50 out of the box but you
can set it to anything you want and make a new Camera Raw Default of course
(meaning, it©ˆs tough to know what a default is other than an
initial setting when the product is first used). Contrast is simple (make
the blacks/whites blacker or whiter).
In most cases, you©ˆll never need to do much
to Brightness and if you do, it©ˆs going to be a tiny tweak. Work
with the four main tone sliders. Then you might want to consider the
Parametric curve.
ACR is going to radically change compared to the old
version you©ˆre reading about. 3.7 is public beta, 4.0 is private
and a major change over 3.X!
Andrew Rodney
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Re: Camera Raw Settings
Posted by: "Lee Varis"
Fri Feb 2, 2007 8:17 am (PST)
The +50 brightness setting is a default setting that
Adobe came up with to emulate the cameras own internal processing for
rendering Jpegs. Just about every camera manufacturer lies about the true
sensitivity of their chip. There good reasons for this (Dan alludes to
these reasons in his book) – by lulling users into underexposing they
insure , somewhat, against the possibility of clipping highlight values.
How you interact with any default depends on how you routinely expose your
images. If you are going to be fully correcting in Photoshop anyway, it
makes sense to default to a totally flat, un- enhanced, raw process setting
(every slider set to zero) so that you are dealing with as much of the raw
data from shadows to highlights as possible. I always test my camera at
these settings to find the ideal ISO for exposure of the chip and thus end
up with the best possible data. The camera meter, however, is almost always
set up for an ISO where there has been some level boosting post capture so
you have to cheat the meter or enter some kind of custom compensation
(bracketing) to get around it. I generally use a hand held spot meter for
serious work and use the camera in manual mode.
regards,
Lee Varis
President, LADIG
Photographer and Digital-Photo-Illustrator
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Re: Camera Raw Settings
Posted by: "John Arnold"
Sat Feb 3, 2007 8:22 am (PST)
Andrew,
Thank you for your explanation. So is setting
Brightness to +50 Adobe's way of compensating for the linear nature of raw
data? That's kind of the conclusion I am arriving at. And this is probably
a question for Dan, because he is the one who applied the curves in the
book. But I am wondering why he chose to substantially darken the image (at
least that's the way it looks to me)and move away from the ACR default,
even though the default initially appears to IMHO look like the better
exposure where the overall brightness level of the image is concerned?
I'm probably overanalyzing the situation. But if there
is some kind of best practice behind the move, I would like to know what it
is.
Thanks.
John Arnold
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Re: Camera Raw Settings
Posted by: "John Arnold"
Sat Feb 3, 2007 8:23 am (PST)
Mark Segal" wrote:
Brightness can range between -/+150. As you adjust, it
shifts mid-
tone values in a non-linear manner much like the grey
input slider in
Levels. The default setting of 50 is Adobe's guess
about a setting
that would be a liveable starting point for image
correction in
Camera Raw.
Mark,
Thanks for the reply. Do you or does anyone else know
"why" they have chosen +50 as a liveable starting point? As Dan
mentions, they use +25 as a starting point for Contrast because most images
require an expansion of the range in the midtones. I was wondering if there
was also some kind of rationale for the Brightness setting. My concern is
this. Does leaving brightness set at the default of +50 in essence apply a
curve to the master channel and if so, shouldn't we avoid that based on
Dan's comments in chapter 16?
It means nothing more than that, and in particular
there is no such thing as "neutral" when it comes to Brightness.
I would agree, neutral is a relative term when speaking
of brightness. However, I remember reading in the late Bruce Fraser's book
"Real World Camera Raw" that cameras do a "linear"
capture of data when it comes to brightness, and that it did not correspond
well to human perception. So I am wondering if Adobe's +50 is an attempt to
show that they have applied some kind of gamma correction to the data.
Whereas leaving it at zero would possibly be the equivalent of a linear
capture?
I generally find it one of the least useful correction
tools in Camera Raw and hardly ever use it - especially since Curves became
part of the Camera Raw arsenal with CS2, and all the more so with the
Parametric and Point Curves options in the new Camera Raw CS3 Beta. I have
no idea where Dan started from in the image to which you refer - I'm merely
making the point that "default" settings should be treated as
starting points and they are only as useful as the images require.
I too have no idea where Dan started from. I just
noticed that when I applied the LAB curves as they are presented in the
book, that I blew the highlights out completely. It was only after I set
Brightness to zero that Dan's Lightness channel correction made sense.
Thanks again for you thoughts on the matter.
John Arnold
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Re: Camera Raw Settings
Posted by: "John Arnold"
Sat Feb 3, 2007 8:24 am (PST)
Lee Varis wrote:
I always test my camera at these settings to find the
ideal ISO for exposure of the chip and thus end up with
the best
possible data. The camera meter, however, is almost
always set up for
an ISO where there has been some level boosting post
capture so you
have to cheat the meter or enter some kind of custom
compensation
(bracketing) to get around it. I generally use a hand
held spot meter
for serious work and use the camera in manual mode.
So in other words, are you saying that you should test
your camera by shooting some test shots and then determine how much
in-camera bracketing is required to get what appears to be a correctly
exposed image when all ACR settings are set to zero?
John Arnold
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Re: Camera Raw Settings
Posted by: "Andrew Rodney"
Sat Feb 3, 2007 11:06 am (PST)
On 2/3/07 8:55 AM, "John Arnold" wrote:
Thank you for your explanation. So is setting
Brightness to +50
Adobe's way of compensating for the linear nature of
raw data? That's
kind of the conclusion I am arriving at. And this is
probably a
question for Dan, because he is the one who applied the
curves in the
book. But I am wondering why he chose to substantially
darken the
image (at least that's the way it looks to me)and move
away from the
ACR default, even though the default initially appears
to IMHO look
like the better exposure where the overall brightness
level of the
image is concerned?
To begin with, there is a difference in the Brightness
settings between older versions of ACR (undoubtedly the copy used in
Dan©ˆs book) and newer versions (3.7 forward) since there needed
to be consistency with ACR and Lightroom. Also note, in these newer
versions, you can edit non-raw files like JPEG and, very important, the
settings used are applied differently to existing rendered files versus Raw
files. An extra negative range is required to edit JPEG/TIFF files, and DNG
files created from JPEG/TIFFs. So whatever you©ˆre reading is
probably out of date or will be real soon now (sorry).
Yes the default (what is better known as the Neutral
Starting point) is set to +50 primarily due to the fact that a zero setting
produces too dark a rendering with most raw images. The default state of
all converters will be different of course. The idea is to provide a fairly
decent rendering as a starting point for you to now work on the image.
You©ˆll notice that in ACR and LR there©ˆs a setting
called Auto which is not the Neutral Starting point but rather, much like
the rendering in-camera, a guess as to what would produce a pleasing image.
You can use that, or Neutral or set anything you like as a new ACR default.
According to Mark Hamburg, the +50 = one stop and this neutral staring
point is necessary for both a good looking starting point and to work with
the controls above it (primarily Exposure, Blacks etc).
Additional changes from the book, Brightness and
Contrast controls are moved upstream of the parametric curve in the
processing pipeline. You may notice there are two Histograms provided (main
and in curves). The B&C controls are reflected in the background
histogram in the parametric curve, but not the tone curve graph.
I'm probably overanalyzing the situation. But if there
is some kind
of best practice behind the move, I would like to know
what it is.
As mentioned earlier and by others working with the
product, leave it alone unless after working with the controls above it,
which are placed there in that order for a reason, they doesn©ˆt
produce a tone curve you desire such that a subtle S shaped curve is
needed. I don©ˆt know what Dan©ˆs talking about here (I
don©ˆt have the book) and the bottom line is, whatever
he©ˆs talking about is old news since 3.7 is available now with
far greater control, a totally different imaging pipeline and version 4.0
is coming real soon with even more rendering options. All this applies to
Lightroom as well.
There is simply no correct way to render the images
other than following the controls in the order they are provided. You are
working with scene referred data and using this converter to produce output
referred data. There are no rules in any of this other than make the image
appear as you wish (again, doing so in the order provided or you'll just
chase your tail in getting the preferred rendering).
As Dan mentions, they use
+25 as a starting point for Contrast because most
images require an
expansion of the range in the midtones.
Contrast is the last setting you should ever need to
touch based on it's order in the processing pipeline in ACR. Again, top
down, left to right (using the various panes).
Contrast in ACR isn't linear like we have in CS2 but
rather another S curve and affected by Brightness so again, work there
first. And unlike Photoshop, altering these controls doesn't affect color
as you'd see in Photoshop rather just luminance (another advantage of doing
all this on Raw data).
So in other words, are you saying that you should test
your camera by
shooting some test shots and then determine how much
in-camera
bracketing is required to get what appears to be a
correctly exposed
image when all ACR settings are set to zero?
Not zero across the boards. Here's what has worked well
for me. I take a precise external light meter (a Minolta Flashmeter III)
under controlled lighting and setup a Macbeth Color Checker. I know the
meter is accurate (within 1/10 of a stop) and get a incident reading at ISO
100. I then set the camera to shoot a bracket at the minimal amount
shooting 2 stops over, 1 stop under the recommended F-stop. I bring all
images into ACR and set Auto off (the old Neutral Setting again). Now I
examine the white patch and look for an exposure in the group that is as
close to clipping without doing so. In the case of my Canon 5D, I found
that actually shooting at ISO 100 provided the correct values above but if
it's off, I simply set exposure compensation on the camera to produce that
exposure. You want to expose for the highlights in digital due to the
linear capture. Ideally you want to exposure to the right, that is, as
close to clipping a highlight that isn't specular without clipping as
possible. Note that the Macbeth white isn't as white nor specularly neutral
as I'd like so I'm also using a white tile that is ( http:
//www.babelcolor.com/main_level/White_Target.htm). With this pup, if I can
get 245/254/254, I'm in really good shape.
Now the issue is correlating the meter in the camera
with the scene since such meters are kind of dumb, thinking everything they
'see' is 18% gray. Using a spot meter mode in the 5D and understanding this
allows me to handle exposure pretty well. So for example, if you know have
your camera meter ISO nailed using the above technique, if you point the
meter at say a white dog on snow, the meter will under expose the scene by
about 2 stops, you simply compensate. The key is nailing the ISO in the
camera meter, then understanding what it's looking at as 18% gray and if
necessary, compensating for this. Of course you could carry around an
external incident meter and just use that as your exposure guide. But at
least you know the chip sensitively and correct ISO to expose for the
highlights.
Andrew Rodney
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Re: Camera Raw Settings
Posted by: Dan Margulis
Sat Feb 3, 2007 4:40 pm (PST)
John Arnold writes,
And this is probably a question for Dan, because he is
the one who applied
the curves in the book. But I am wondering why he chose
to substantially
darken the image (at least that's the way it looks to
me)...
No, I didn't darken it. Camera Raw wanted to
substantially *lighten* it, and I did not give it permission to do so.
...and move away from the ACR default, even though the
default initially
appears to IMHO look like the better exposure where the
overall brightness level
of the image is concerned?
An inexperienced person attempting to correct an file
often creates problems for the next person who has to handle it. This is
why a professional retoucher will always ask for the *original* file to
work from, rather than something that somebody else has attempted to
improve. The "corrected" version probably looks better than the
original does--but the person who did it likely engineered in some problem
that makes the file more difficult to improve than if we started from
scratch.
The same thing can happen when acquiring a digital
image, whether from a camera, Camera Raw, or any other acquisition module.
Artificial intelligence often attempts to "improve" the image
before we see it, by forcing a white and/or black point and by increasing
midtone contrast at the expense of highlights and shadows.
These features wouldn't be in there if they didn't work
most of the time, but in a lot of images they actually make matters worse,
such as when highlight and/or shadow detail is critical, or where there are
bright colors that have to retain shape. In those cases, they may make
subsequent correction more difficult (as in the image you're talking about)
or even, IMHO, impossible (as in the flower image in the same chapter).
The utility of raw capture modules is that they can
bypass these "corrections" when necessary. To take advantage of
them doesn't require a recipe--I use a zero setting as a matter of
convenience. It just means choosing very conservative numbers to ensure
that the image isn't damaged when you open it.
If we're fortunate enough to have a neutrally correct
(or nearly so) capture, then opening the endpoints in Camera Raw won't hurt
anything. But if there *is* a cast, then opening the endpoints makes life
unnecessarily difficult. If we do, in addition to making the endpoints
lighter and darker, Camera Raw forces them to be more neutral, a bad idea.
Yes, if you compare the two images as if they were
final products, the one with the full range looks better. But that's not
the object of the game. The question is not which one looks better *now*,
but which one looks better after we've corrected it. The choices are
starting with a relatively flat image that has a uniform cast at all levels
of darkness versus a relatively contrasty one whose highlights and shadows
are neutrally correct but is wrong everywhere else. The first takes seconds
to fix and no great skill. The second looks better now but is rather
difficult to improve further.
Dan Margulis
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Re: Camera Raw Settings
Posted by: "alpom111"
Sat Feb 3, 2007 4:40 pm (PST)
"John Arnold" wrote:
And this is probably a
question for Dan, because he is the one who applied the
curves in the
book. But I am wondering why he chose to substantially
darken the
image (at least that's the way it looks to me)and move
away from the
ACR default, even though the default initially appears
to IMHO look
like the better exposure where the overall brightness
level of the
image is concerned?
What Dan said is he ZEROED everything in ACR and then
open the image in PS.
Alcides Pomina
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Re: Camera Raw Settings
Posted by: "John Arnold"
Sat Feb 3, 2007 4:40 pm (PST)
Andrew Rodney wrote:
Yes the default (what is better known as the Neutral
Starting point) is set
to +50 primarily due to the fact that a zero setting
produces too dark a
rendering with most raw images. The default state of
all converters will be
different of course. The idea is to provide a fairly
decent rendering as a
starting point for you to now work on the image.
You©ˆll notice that in ACR
and LR there©ˆs a setting called Auto which
is not the Neutral Starting point
but rather, much like the rendering in-camera, a guess
as to what would
produce a pleasing image. You can use that, or Neutral
or set anything you
like as a new ACR default. According to Mark Hamburg,
the +50 = one stop and
this neutral staring point is necessary for both a good
looking starting
point and to work with the controls above it (primarily
Exposure, Blacks
etc).
This makes sense to me now that you mention it. In
other words, if you reset endpoints etc., some sort of brightness move will
have to be made.
Contrast in ACR isn't linear like we have in CS2 but
rather another S curve
and affected by Brightness so again, work there first.
And unlike Photoshop,
altering these controls doesn't affect color as you'd
see in Photoshop
rather just luminance (another advantage of doing all
this on Raw data).
I didn't know that the Brightness slider doesn't affect
color. That makes it a lot more of a desirable control.
Thanks very much for the great explanation. It shed a
lot of light on the matter.
John Arnold
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Re: Camera Raw Settings
Posted by: "MARK SEGAL"
Sat Feb 3, 2007 4:40 pm (PST)
Andrew,
Like all recipes that may have some general validity,
this one should not be followed slavishly. For example, beyond the White
Balance, the Exposure slider would generally not be my preferred starting
point. I find most images have problems that need to be more specifically
targeted than possible with the Exposure slider. I find myself dealing with
highlight and shadow values using Recovery, Fill and Black before tinkering
with Exposure. And if there are "Exposure" problems, I find I can
generally solve these better in terms of overall tonality by going straight
to the "T" tab and working on either the Point or Parametric
Curve, depending on the nature of the correction to be made. I agree with
you that the main objective is to make the image appear as desired, but I
haven't found myself chasing my tail by disobeying the "order
provided".
Mark Segal
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Re: Camera Raw Settings
Posted by: "Rich Wagner"
Sun Feb 4, 2007 4:14 am (PST)
On Sat, February 3, 2007 3:43 pm, MARK SEGAL wrote:
Like all recipes that may have some general validity,
this one should not
be followed slavishly. For example, beyond the White
Balance, the
Exposure slider would generally not be my preferred
starting point.
I haven't spent much time yet with the new ACR, but I
tend to work "top to bottom" as well. I fix the color temperature
and exposure, then work my way down. Slavish? Nope - just weems to work
well. If I don't fix exposure errors first, I seem to end up in a loop.
I find most images have problems that need to be more
specifically targeted
than possible with the Exposure slider. I find myself
dealing with
highlight and shadow values using Recovery, Fill and
Black before
tinkering with Exposure. And if there are
"Exposure" problems, I find I
can generally solve these better in terms of overall
tonality by going
straight to the "T" tab and working on either
the Point or Parametric
Curve, depending on the nature of the correction to be
made. I agree with
you that the main objective is to make the image appear
as desired, but I
haven't found myself chasing my tail by disobeying the
"order provided".
I'll be spending a lot of time with CS3 and Lightroom
the next two weeks -I'll see if my habits change given the new tools. For
me, setting the exposure and shadow is analogous to setting the black and
white points on a scanned image. It would seem strange to not adjust these
first.
--Rich Wagner
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Re: Camera Raw Settings
Posted by: "Rich Wagner"
Sun Feb 4, 2007 4:14 am (PST)
On Sat, February 3, 2007 1:27 pm, alpom111 wrote:
What Dan said is he ZEROED everything in ACR and then
open the image in
PS.
I still don't understand the rationale for doing this.
You have a 16-bit, wide-gamut internal working space to optimize the image
in before converting it to an output space (of your choice). Any
corrections possible should be made in that space (with the desired output
space selected when making corrections) - that's what it was designed for.
PS should be used for corrections that are not possible in ACR.
--Rich Wagner
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Re: How to evaluate Photoshop technicians
Posted by: "new_news"
Sat Feb 3, 2007 5:26 pm (PST)
I appreciate all the responses to my question. All lot
of good answers. The one that comes closet to what I had in mind was
written by Lee Clawsen.
I ask them what they know about photography. And we
look at both good and
bad images (color and B&W prints usually). Being
able to visually analyze an
incoming picture or group of them gives me a sense of
how they see rather
than what tool/technique they'd use.
I am in the fortunate position of being able to hire
someone who is not expert, or even particularly experienced, in Photoshop.
I'm willing to train him or her. But I need to have someone with a good
eye, and I don't know how to train someone to "see" what I want
them to see. I can explain color, contrast, perspective, etc., to some
degree but that only goes so far.
There are (at least) two problems finding a person like
that: I don't know how to do a proper evalution, and even if I did, an
untrained person might not have the knowledge of how to express himself
regarding the image concepts I'm trying to evaluate. I think I may be
looking for the type of testing a psychologist might do.
In the meantime, I'm going to start using Lee's method.
Jonathan Clymer
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Re: Camera Raw Settings
Posted by: "John Arnold"
Sun Feb 4, 2007 8:24 am (PST)
Rich,
I think what I hear Dan saying is that many of the
controls in ACR are somewhat primitive compared to Photoshop at this point
because they do not allow for channel by channel corrections. As a result,
even though ACR delivers a 16-bit wide gamut working space, the potential
casts that could be introduced by using ACR in the areas that Dan cautions
us to avoid has now created problems that could, depending upon the image,
be far more difficult to correct than if you had just taken the image in
it's completely neutral zeroed out state, and worked with it from there.
John Arnold
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Re: Camera Raw Settings
Posted by: "Stephen Marsh"
Sun Feb 4, 2007 8:24 am (PST)
Rich, it no doubt depends on the image, and the user.
Different courses for different horses. The end image is what matters to
Dan, not so much how one gets there (my perception is that Dan thinks the
market hype on camera raw is overstated). A less skilled user of Photoshop
than Dan, may get better results doing most of the work in the camera raw
converter, than in Photoshop (even more so with later raw converter
software versions). Dan may get better results with a "flat"
zeroed image, despite the theory saying that his non linear gamma encoded 8
bpc small gamut RGB edits and lossy LAB/CMYK conversions will lead to an
inferior result. Dan can make a silk purse out of a sow's ear - a zeroed
raw conversion may be nowhere close to a pig.
Back in scanning, there were two main camps - those
that did as much work as possible when setting up the prescan, or those
that scanned flat with headroom and edited in Photoshop using a custom
scanner profile as input to an editing space. Scanners even introduced a
'digital negative' or archive that one could use the scanner software on,
even after the original flat raw scan.
It may not be fair to compare a high bit wide gamut
scanner RGB editing workflow with linear high bit digital camera raw
images, but some do use a similar general approach.
Obviously Dan would take advantage of the RAW converter
where necessary and where it offers benefits such as highlight recovery,
there is nothing stopping one from combining various flat or tweaked raw
conversions into a composite in Photoshop (just as is common for bracketed
exposures).
As mentioned in recent posts, automated corrections can
make later edits harder. Although raw conversion edits may be human
performed and not as bad as automated ones, in some images and edits Dan
may get better results with a flat image. Your mileage may vary!
P.S. An 'output space of your choice', as long as it is
one of four hard wired profile choices in ACR and not any installed profile
as in Photoshop proper (better than the model T option I guess).
Sincerely,
Stephen Marsh.
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Re: Camera Raw Settings
Posted by: "Andrew Rodney"
Sun Feb 4, 2007 8:25 am (PST)
On 2/3/07 3:43 PM, "MARK SEGAL" wrote:
Like all recipes that may have some general validity,
this one should not be
followed slavishly. For example, beyond the White
Balance, the Exposure slider
would generally not be my preferred starting point. I
find most images have
problems that need to be more specifically targeted
than possible with the
Exposure slider. I find myself dealing with highlight
and shadow values using
Recovery, Fill and Black before tinkering with
Exposure.
You are more than welcome to work with the product in a
method that isn©ˆt recommended by those who built it. The bottom
line is, can you render the image as you wish? But usually its a good idea
to handle the big imaging issues first. Yes, white balance is the
recommended first correction and Exposure is the way to set the white
clipping after which, you can use the recovery to bring back any clipped
white values that may have clipped in the process or exposure assuming one
of the three channels has any data. Try that with an existing rendered
image; ain't going to happen!
The highlight recovery, the new Fill Light and all the
other controls below Exposure ARE based on the settings you apply in
Exposure. Operating in a different order can work but you will likely find
you©ˆre taking two steps forward, one step back due to the
processing order of the edits in the two converters being discussed.
And if there are "Exposure" problems, I find
I can generally solve these
better in terms of overall tonality by going straight
to the "T" tab and
working on either the Point or Parametric Curve,
depending on the nature of
the correction to be made. I agree with you that the
main objective is to make
the image appear as desired, but I haven't found myself
chasing my tail by
disobeying the "order provided".
You may or may not chase your tail depending on the
order you apply the edits and the degree of the edits. For example, it is
generally suggested that you fix white balance before exposure or a color
cast before applying a saturation adjustment. That©ˆs usually the
case with rendered image corrections in Photoshop as well as in a raw
converter. But If you can produce a desired rendering by working backwards,
so be it. It©ˆs just a bit more work to adjust say saturation
before setting black and white point or fixing a color cast. That
isn©ˆt to say you can©ˆt do this, it©ˆs
usually a lot more work.
Thomas Knoll built the tools in a specific order but if
you find you©ˆd prefer to work differently, by all means do so
but be aware that corrections are happening in a fixed order in ACR and
Lightroom.
On 2/3/07 5:25 PM, Dan Margulis wrote:
If we're fortunate enough to have a neutrally correct
(or nearly so) capture,
then opening the endpoints in Camera Raw won't hurt
anything. But if there
*is* a cast, then opening the endpoints makes life
unnecessarily difficult.
Considering that raw data has no color, its Grayscale
data, I don©ˆt understand how a cast could be an issue unless you
make a cast based on your rendering decisions. The recommended first
correction in ACR and LR is white balance the correct or 'neutral' setting
being whatever you wish it to be. The white balance at capture has
absolutely no bearing on the white balance of the rendered Grayscale raw
data. It©ˆs a suggestion you can apply or completely ignore. The
ONLY area where the raw data is affected is ISO and exposure.
The question is not which one looks better *now*, but
which one looks better
after we've corrected it.
Corrected it? You're building a color image from data
that has no color. The best, fastest and most flexible approach is to do
all the heavy lifting at the raw conversion process because
you©ˆre dealing with linear encoded data, the corrections are
totally non damaging and applied in high-bit and you can change your mind
about the rendering as many times as you wish (look at Virtual Copies once
you get your hands on the final version of LR or when using ACR with Smart
Objects). That isn't the case with a pre existing rendered image.
Try this: make two renderings of the same raw, one for
shadows, one for highlight and even play with differing white balance. Drag
and drop the rendered images in Photoshop on top of each other (use shift
key) so they are in pin registration. Double click on top layer and play
with blend if options using feathering. You'll produce a vastly superior
tonal range than one flat raw conversion with excessive Photoshop edits for
tone. Here's where you want to now use Photoshop until ACR/LR has such
blending layer options (it will come in time).
The choices are starting with a relatively flat image
that
has a uniform cast at all levels of darkness versus a
relatively contrasty
one whose highlights and shadows are neutrally correct
but is wrong everywhere
else.
It doesn©ˆt have to be an either or
situation. Setting ACR or LR to produce a flat appearing image using fast,
metadata corrections to then have to Œfix©ˆ it as a full
resolution pixel based image in Photoshop is totally non-productive for
anyone working with raw data, certainly if they have dozens of similar
images. This Œfix a big image©ˆ one pixel at a time in
Photoshop is very 20th century thinking and it might appeal to a few but
not anyone shooting seriously who has to render lots of images. Do the big
work in ACR or LR, bring a corrected file into Photoshop for the pixel
polishing, a process in which it was designed.
A raw image and the process of rendering isn't anything
like correcting a rendered image! The tools, the data encoding and the
workflow are not at all the same. If you have an ugly transparency, you can
attempt to correct the issues at the scan stage but there's only so much
one can do. A raw image initially has no color, its scene referred and your
job is to produce an output referred image which isn't the same as
'correcting' an image since the rendering options are vastly more variable
and powerful.
Producing a flat image in ACR to then tone map it in
Photoshop is like setting a scanner in a default mode and doing corrections
after the scan instead of tweaking the controls to produce a corrected
scan. I don't understand why anyone would do this.
This is a lot like the differences in handling a color
neg versus a color transparency. The rendering on the color transparency is
baked into the chrome, you only have so much leeway in what you can fix.
Not the case with a color neg, you have an infinite number of possible
filter packs to handle the color rendering. A raw file has vastly more tone
and color possibilities than any color neg.
Andrew Rodney
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Mark Segal"
Sun Feb 4, 2007 8:25 am (PST)
Rich,
As with everything in Photoshop we each use what seems
to work best for ourselves, but when a response like this comes back I have
a bad habit :-) of saying "now wait a minute, what am I missing
here?". As it happens, I'm now processing a large photoshoot I did in
Barcelona last October. So I have these 340 raw images tabulated in Bridge
and I ran through them all to find one that is truly and unambiguously
under-exposed - i.e. not just highlight and shadow problems but really
throughout the range under-exposed - because I said to myself if there were
a sure-fire reason to use the Exposure correction first, it would be to
address true overall under-exposure. Interestingly, I could only find ONE
of 340 images that fit this definition (which indicates I don't
under-exposure very much, which is perhaps one of the reasons I seldom need
this tool). The under-exposure was on the roof of La Pedrera (Gaudi's Casa
Mila) - easy to happen there because the overall brightness is so high that
unless one is really careful the camera can be fooled. The image has traces
of blue sky, billowing clouds ranging from near-white to below mid-grey,
and those beige-ish Gaudi chimneys and vents resembling abstract sculptures
(which should occupy a range around the mid-tones). The general objective
is to shift the histogram to the right, the binding constraint being
without blowing-out highlights. There are at least two ways: Exposure
Slider and Curves (Point and/or Parametric). So I tried each starting from
"default" settings of Brightness 50, Contrast 25 and Linear
Curve. The Exposure slider certainly worked, but by the time the brightest
points of the clouds were about to blow-out, the mid-tones were wishy-washy
such that tonal modulation of the sculptures was unsatisfactory. So I went
back to square-one, opened the "T" tab, went to the Point Curve,
grabbed the upper right handle and simply shifted it leftward, steepening
the curve until just before the highlights in the clouds were ready to
blow. Far better result - nice mid-tones with far better modulation of the
sculptures and gorgeous clouds. (Of course this is happening because the
curve affects brightness AND contrast simultaneously due to the slope -
with less impact on the mid-tones than results from a direct attack with
Exposure.) To improve it a bit more I went to the Parametric Curve, slid
the break-point between Lights and Darks further to the left of Default (to
better target the Darks) and shifted the Dark parameter positive 9. This
just breathed a little more life into the three-quarter tones. A happier
image.
I described this in a bit of detail, because it is
typical of the kind of outcomes I have discovered with this workflow. Just
after Christmas I was processing a wedding shoot (a favour for a relative)
where photo-flash produced all kinds of exposure issues that were
challenging to deal with, and here too I found the Exposure slider on the
whole less useful than going straight for the "T" tab.
I've taken an interest in Camera RAW CS3 workflow, so
I'm now starting an archive of screen-captures showing "what happens
when". If you would like to see the three screen captures of the La
Pedrera shot in ACR (original, Exposure Correction, Curves correction),
just send me your email address.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Mark Segal"
Sun Feb 4, 2007 10:18 am (PST)
I think what I hear Dan saying is that many of the
controls in ACR
are somewhat primitive compared to Photoshop at this
point because
they do not allow for channel by channel corrections.
John Arnold
The clinchers are "primitive" and "at
this point". "At this Point" is no longer CS2, because the
new ACR is so much richer than its predecessors that all the books about
this need to be re-written. Lightroom and the new ACR offer so much refined
control over colour and tonal correction that they really require us to
re-think important aspects of workflow.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "MARK SEGAL"
Sun Feb 4, 2007 10:18 am (PST)
Andrew,
Thanks for your permission to work with the product in
a manner that isn't recommended by those who built it, but as the product
is in Beta and has no instructions on paper or on-line, they haven't
explicitly recommended anything about workflow for this version of the
product. That much said, you are probably correct one can infer that they
intend this workflow from how they set-up the tools - at least as far as
the logic of handling the biggest-picture adjustments first. I don't
believe. however, this necessarily means - or even they necessarily think -
that other workflows are inferior. I can ask Thomas about this next time I
see him, but until then my experience and common-sense prevails.
Whether I use the "T" tab or the Exposure
slider first, I am handling the big issue that comes next after White
Balance (on that we agree), except in a different way, and I have NEVER YET
chased my tail - at least not in photo image editing - would that the rest
of life were so straight-forward! :-)
The ostensible evidence fromm trying to do similar
things in different ways indicates to me that the corrections are happening
in the order I implement them, regardless of how the tools are laid-out in
the inter-face.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Pajuaba Gmail"
Sun Feb 4, 2007 1:37 pm (PST)
I couldn´t agree more. For instance, on some
images, I prefer to set the contrast at zero, or near it, and increase the
contrast by moving the Shadow slider. Some images come better this way,
some not. In conjunction with some moves on Brightness it´s a way to
have more control over shadow contrast, instead of the general Contrast
slider.
Regards,
Rodolpho Pajuaba
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Andrew Rodney"
Sun Feb 4, 2007 1:38 pm (PST)
On 2/4/07 9:11 AM, "John Arnold" wrote:,
I think what I hear Dan saying is that many of the
controls in ACR
are somewhat primitive compared to Photoshop at this
point because
they do not allow for channel by channel corrections.
Actually many of the controls in ACR/LR are vastly more
powerful than what you©ˆd find in Photoshop! Some, not all (and
vise versa). Take a look at Vibrance as just one example. There's nothing
in Photoshop like it.
You may need to edit color channels in baked rendered
color images. That's not what's happening in this case. Until you export
the data based on the metadata instructions, there's no color, and you can
produce as many variations as you wish without damaging (or even creating)
a pixel. And do it REAL FAST!
These are different tools that provide different
capabilities and someone who's spent too long falling in love with
Photoshop's ability to correct images without really looking deep into what
raw processing offers needs to take the blinders off quickly. Again gang,
raw has no color. You decide what you want the initial color to be long
before pixels are built for editing in Photoshop.
Photoshop can be the ultimate turd polisher but the
question becomes, why start with a turd? True, you could under or over
expose the raw data and be stuck with potentially very poor data.
Photographers tend to try not to do this. One problem with raw data for
some is, your likelihood of having a trud to polish is greatly diminished
if you simply exposure correctly. White balance off? Not an issue. Color
cast? You made it based on the rendering controls you affected. Blown out
highlights? As long as there's one channel of data, the other two can be
rebuilt. Raw files can provide up to an additional stop of tonal data for
rendering, a rendered image is what it is.
As a result,
even though ACR delivers a 16-bit wide gamut working
space, the
potential casts that could be introduced by using ACR
in the areas
that Dan cautions us to avoid has now created problems
that could,
depending upon the image, be far more difficult to
correct than if
you had just taken the image in it's completely neutral
zeroed out
state, and worked with it from there.
As I stated, you can pretty much render the Grayscale
data to appear anyway you wish IF you understand how the controls work.
Also, many of these tools that affect tone do not affect color shifting due
to how the raw data is handled. Something that's promoted here as a 'big
deal' using LAB. Lastly, anything written about the beta of Lightroom or
the old version of ACR in a book you currently have is outdated by a pretty
significant degree.
On 2/4/07 9:39 AM, "MARK SEGAL" wrote:
Thanks for your permission to work with the product in
a manner that isn't
recommended by those who built it, but as the product
is in Beta and has no
instructions on paper or on-line, they haven't
explicitly recommended anything
about workflow for this version of the product.
Actually this workflow has been documented almost as
long as ACR has been a product. While like Dan's book, it's now seriously
outdated, Bruce Fraser's Real World Camera Raw (1st and 2nd edition)
discusses this concept. And again, you don't have to use the product as
designed but for those reading these posts who may not have your technical
abilities with the product, its good advise to START top down, left to
right. But as I've said from day one, the beauty of working with scene
referred raw data is as long as you achieve the color and tone you wish,
anything is fair game. Its fast, its non destructive, its infinity
variable.
The ostensible evidence fromm trying to do similar
things in different ways
indicates to me that the corrections are happening in
the order I implement
them, regardless of how the tools are laid-out in the
inter-face.
From purely a technical standpoint in how the product
applies the edits, that's incorrect but, if you're happy with the results,
that's all that matters. Play around with the various tone controls and
look at BOTH histograms and I think you'll see that there are fixed orders
to how the edits are applied to the data. That's by design of course.
The clinchers are "primitive" and "at
this point". "At this Point" is no
longer CS2, because the new ACR is so much richer than
its predecessors that
all the books about this need to be re-written.
Lightroom and the new ACR
offer so much refined control over colour and tonal
correction that they
really require us to re-think important aspects of
workflow.
Yup!
A rejoinder on the workflow issue - and something that
hasn't been mentioned
yet. At the raw conversion stage we don't have a
printer profile. Therefore we
cannot fine-tune luminosity in a soft-proof mode. Hence
until there comes a
way to soft-proof in ACR or in Lightroom, we will still
need Photoshop to make
the final pre-printing adjustments.
I've been begging for soft proofing in LR since day one
and hopefully that will come since you can print (very effectively) out of
Lightroom. In fact, it makes printing out of Photoshop seem prehistoric
when you work with the templates which can hold every print parameter
(paper type, profile, output rez etc). Mac Holbert at Nash Editions is not
printing most of his work out of LR due to this ease of use.
However, I'd be hard pressed to edit anything but a
virtual copy for output once I do have soft proofing. That is, I'd like to
produce and maybe render a master file that's corrected for all subsequent
output needs as I currently do in Photoshop, then load a soft proof and
edit based on the output device.
What I hope to see in LR (we Alpha's are working hard
on new feature requests) is a print history in which you could click on a
history state in LR for any printing and corrections for that output device
and be done. So it would be like adjustment layers in layer sets per output
device but all this is accomplished using metadata instructions instead of
a pile of huge, pixel based images. It would save a ton of time and HD
space. Obviously if you need to do Photoshop work, you'll have to render
the file first. With the new cloning and healing tools in version 1.0,
there's a lot of work that can be accomplished solely in Lightroom, never
having to be rendered as a PS file. But this is a 1.0 version product. Lets
not forget what Photoshop 1.0.7 was capable of and cut LR a bit of slack.
Time will come where 80%+ of many users work will be accomplished
completely in LR instead of Photoshop.
Resist the urge to render the files in Photoshop just
because that's been the way we've worked for 16 years. Yes, this will be
necessary but how often? Less and less I'll bet.
Andrew Rodney
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Richard Wagner"
Sun Feb 4, 2007 5:15 pm (PST)
Mark,
Please send the screen captures - my email address
should be at the top of the CT message header, but in case it's not, use
Rich@WildNaturePhotos.com I'll be spending a *lot* of time with CS3/ ACR
after I get home in 2 days - I'll give your workflow a try. It's certainly
possible that you've hit on something that even the designers of ACR may
have missed, and there's certainly benefit to experimentation. Because the
workflow "made sense" to the engineers in the order they've set
things up, they may not have even tried your method. I've spent little time
up until now with the new ACR, which is greatly changed from the old ACR,
so until I try what you describe, for me, all bets are off.
It is nice to have these new, powerful tools coming
out, although it will take some time to really get to know them. And I
agree - soft proofing in Lightroom/ACR would be the coup-de-grâce to
Photoshop from the photographer's perspective.
Thanks,
--Rich Wagner
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: Mark Segal
Sun Feb 4, 2007 5:16 pm (PST)
OK Andrew, I tried what you said (hope I understood you
correctly) and I don't see how it shows any fixed order for doing things.
Whether I start editing luminosity in the "B" tab or the
"T" tab, the histogram adjusts in the expected manner in both
places, as one would expect it should. So what have I proven (or not proven
:-))?
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "George Machen"
Sun Feb 4, 2007 6:04 pm (PST)
RAW Developer v1.6 has curves for individual RGB
channels (and individual LAB channels, too). It's not clear to me from
their documentation whether these individual channel adjustments actually
are some kind of white balance movements, or represent post-processing
after rendering, or what. Can anyone explain what RAW Developer's
individual channel curve adjustments really are doing?
- George Machen
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Andrew Rodney"
Sun Feb 4, 2007 6:05 pm (PST)
On 2/4/07 5:55 PM, "markds0" wrote:
OK Andrew, I tried what you said (hope I understood you
correctly) and
I don't see how it shows any fixed order for doing
things. Whether I
start editing luminosity in the "B" tab or
the "T" tab, the histogram
adjusts in the expected manner in both places, as one
would expect it
should. So what have I proven (or not proven :-))?
The Histogram in what you©ˆre calling the T
tab (which in my version, there are icon©ˆs (don©ˆt
ask)) isn©ˆt affected by a change in Brightness slider while the
upper Histogram is. There are two different Histograms! That©ˆs
due to the order in which the tone curves are applied. If you©ˆre
not seeing this we should talk off list because there may be some minor NDA
issues going on here (the version of LR and ACR I©ˆm using may
not be the same as you).
There are two paths in the engine where tonal edits are
applied, before or after the parametric curve that's my point. And this was
done by design. You don't have to follow the logic of this approach of
course but, there are reasons it was implemented. There's a reason why two
proprietary profiles are used. There's a reason why the encoding color
space was chosen. You get the idea.
Andrew Rodney
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Mark Segal"
Mon Feb 5, 2007 3:57 am (PST)
Andrew,
Yes, correct, there are two histograms in the T tab -
the upper one which shows colour channels and the lower one which is grey.
In the B tab there is only the upper histogram which is identical and
behaves identically with the upper histogram in the T tab. Now, based on
what you say about what changes when - in the version I am using, which I
believe is the most recent public Beta, the grey histogram in the T tab
does not change when doing point and parametric curve edits in that tab -
but the upper one does. If, however, I go back to square one and say
increase the Exposure in the B tab, then revert to the T tab, the lower
grey histogram has indeed shifted to portray the change made to Exposure in
the B tab. All that means to me is that the grey histogram in the T tab was
put there as an aide-memoire so that anyone proceeding to the T tab will be
reminded where they've reached in the editing trail. But so what? I might
be terribly thick this evening (or perhaps always, who knows :-), but I
still don't see what this proves about the optimum order of the workflow.
We can continue this off-line if you prefer; I made this observation here
because I suspect it is generic regardless of version details; but as an
Alpha you would know that better than me. I'm not even a Theta - just a
User (with two eyes and some scene-referred grey cells :-).
Mark Segal
___________________________________________________________________________
Re Camera Raw Settings
Posted by: "Mark Segal"
Sun Feb 4, 2007 10:20 am (PST)
A rejoinder on the workflow issue - and something that
hasn't been mentioned yet. At the raw conversion stage we don't have a
printer profile. Therefore we cannot fine-tune luminosity in a soft-proof
mode. Hence until there comes a way to soft-proof in ACR or in Lightroom,
we will still need Photoshop to make the final pre-printing adjustments.
This of course is completely consistent with the point made by others that
neither ACR nor Lightroom are intended as complete substitutes for
Photoshop; however, the addition of soft-proofing capability to either the
new ACR or Lightroom, if technically possible, would eliminate one more
need to revert to Photoshop.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Richard Wagner"
Sun Feb 4, 2007 5:15 pm (PST)
Mark,
In thinking about this evolution of workflow, the other
essential missing component from LR (AFAIK) is sophisticated multi-pass
sharpening, as with PhotoKit Sharpener. Unless I can do capture sharpening,
creative sharpening, and output sharpening from within LR, I'll be making
trips to Photoshop, although all but creative sharpening would be batch
processed. If it's not there now, I'm sure it will just be a matter of time
until it is. I guess my other thought would be RIP support - I hope the
major RIP writers are paying attention.
--Rich
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "MARK SEGAL"
Sun Feb 4, 2007 6:04 pm (PST)
Rich,
It wouldn't surprise me in the least to see Photokit
Sharpener appear one of these days as a Lightroom module. It is a natural.
And you are right - for me as well the ability to use this tool will
continue to require a trip back and forth to Photoshop until it does become
a module. Fortunately there is flexibility in the Photokit Sharpener
workflow about when one applies Capture Sharpening. Where I disagree though
is on the point about batch processing. This would only be recommended if
all the images had similar characteriistics from a sharpening perspective.
If you haven't read Bruce Fraser's book on sharpening yet, let me suggest
it is a worthwhile read. It deals with all the principles behind Photokit
Sharpener (but not the product itself) and reading this one learns why the
various choices the program offers are meaningful and important to set
correctly for optimum results. As for RIP support, over time I can see the
Print module of Lightroom displacing more and more functions that a RIP
provides.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Richard Wagner"
Mon Feb 5, 2007 8:32 am (PST)
On Feb 4, 2007, at 6:34 PM, MARK SEGAL wrote:
This would only be recommended if all the images had
similar
characteriistics from a sharpening perspective.
They do, or they don't get batched.
If you haven't read Bruce Fraser's book on sharpening
yet, let me
suggest it is a worthwhile read. It deals with all the
principles
behind Photokit Sharpener (but not the product itself)
and reading
this one learns why the various choices the program
offers are
meaningful and important to set correctly for optimum
results.
I have it, but have not quite finished reading it. I
agree, it is an excellent book, and I'd say it is currently the definitive
book on image sharpening. Obviously, I don't batch creative sharpening. If
there's any question regarding output sharpening, I run the batch and save
the images with layers, then inspect each, adjust as necessary, flatten and
save.
--Rich Wagner
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Lee Varis"
Mon Feb 5, 2007 8:33 am (PST)
There has been considerable smoke blowing and NDA
threatening discourse going on around working methods for ACR. The basic
operating principles of this plug-in haven't changed but that also doesn't
mean that new features might introduce new ways of working within the
interface. The fact is that the order that you make slider adjustments is
somewhat flexible in that nothing really happens until you click Open or
Save! Certain slider adjustments have an interdependent relationship
however so that Curve adjustments and Exposure/Shadow/Brightness/Contrast
affect the image together. If you start with Curves that will affect where
you start with the sliders - the "tabs" do not force an order
otherwise when you back up to a previous tab the image would revert to a
previous state. The is some logic in the way the controls are laid out but
the interface is not so fascist.
Everything you do in ACR affects everything else to a
certain degree and the biggest problem with ACR is that often its hard to
figure out the interactions. When you are in the Exposure/Contrast slider
area you can't really tell what's happening to the overall curve except to
see the result in the image – if you go to the curve after doing
slider adjustments you see a preset shape or a linear curve (depending you
how you set your defaults) this curve does not reflect the adjustments
you've made elsewhere! You also can't evaluate the adjustments on a per
channel basis except by looking at a histogram overlay. There is little
precision feedback provided – you can only see RGB numbers from the
chosen output profile – no LAB, no CMYK. Hue and saturation moves are
similarly intertwined in different "tabs". If you are seriously
trying to optimize the image using the controls in ACR you almost HAVE to
bounce around, back and forth, from tab to tab and back until you have the
look you're after. At this point, again, if you're serious about optimizing
the image – you open the image in Photoshop, look at individual
channels, read LAB and/or CMYK numbers and figure out where you really are!
Given the limitations of the interface (and please,
this is obvious regardless of features like Vibrance) Dan has suggested
taking a conservative approach to the adjustments you apply in ACR. (
Andrew, before you jump on this, please READ Dan's book) This makes perfect
sense in a "one image at a time" workflow. However, for many
photographers this is not practical when dealing with a large volume of
images that have to be delivered to a client. Fortunately, if you've done
your homework and tested your camera to optimize your ACR settings (at
least visually) to your shooting style, you shouldn't have to do that much
in ACR to get a reasonably good image. For most commercial applications ACR
can deliver a good enough image to satisfy most clients with minor slider
adjustments. Problem images – underexposed, overexposed or
unusual/uncontrolled lighting conditions WILL require different strategies
in ACR/Photoshop to fully optimize the image and I would not try to do
everything in ACR just because it has new Hue/Saturation adjustments or a
Vibrance slider.
regards,
Lee Varis
President, LADIG
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Lee Varis"
Mon Feb 5, 2007 8:34 am (PST)
On Feb 3, 2007, at 8:05 AM, John Arnold wrote:
So in other words, are you saying that you should test
your camera by
shooting some test shots and then determine how much
in-camera
bracketing is required to get what appears to be a
correctly exposed
image when all ACR settings are set to zero?
Yes...
regards,
Lee Varis
President, LADIG
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Andrew Rodney"
Mon Feb 5, 2007 11:57 am (PST)
On 2/4/07 6:51 PM, "George Machen" wrote:
RAW Developer v1.6 has curves for individual RGB
channels (and
individual LAB channels, too). It's not clear to me
from their
documentation whether these individual channel
adjustments actually
are some kind of white balance movements, or represent
post-processing
after rendering, or what. Can anyone explain what RAW
Developer's
individual channel curve adjustments really are doing?
First off, I©ˆm a big fan of this product
with respect to beautiful rendering it produces. I asked Brian your
question, here©ˆs his reply:
Hi Andrew,
The RGB curves on the Curves tab pane in RAW Developer
work just like
the RGB curves in Photoshop or other image editors.
Individual R, G
or B adjustments apply the curve adjustments to the
selected single
color channel in the users specified RGB working space.
With
individual color channel adjustments curves can be used
to do
complex, multi-point white balance adjustments.
The LAB curves are also just like LAB curve adjustments
in Photoshop,
the only difference is that the RGB to LAB and back to
RGB conversion
steps are performed automatically in RAW Developer
compared to having
to do the manual RGB to LAB mode change in Photoshop.
As the full processing pipeline in RAW Developer is
basically
re-rendered from RAW image data on every adjustment
change the round
trip RGB to LAB to RGB conversion is only done once.
Some people have
been concerned (based on some Photoshop articles/books
written more
with an 8 bits/channel image workflow in mind) that a
repeated RGB to
LAB conversion could degrade the image somewhat and
that every time
the LAB curves were adjusted in RAW Developer yet
another RGB to LAB
and back conversion was being done on the image data.
This is not the
case, all processing is done at 16 bits/channel or
higher bit depths
and color space conversions are performed only as
necessary in a
single, full pass through the processing pipeline.
Brian Griffith
Iridient Digital
Now we can debate again the effects of RGB to LAB to
RGB on 8-bit conversions <g>.
On 2/5/07 9:01 AM, "Lee Varis" wrote:
There has been considerable smoke blowing and NDA
threatening
discourse going on around working methods for ACR.
Caution, not smoke blowing but thanks for the kind
words. Not knowing your relationship with Adobe as either an Alpha or Beta
tester, let me simply say that I know for a fact that the discussion of
Lightroom beta 5 (now RC) can be discussed publicly while ACR 4.0 may not
necessarily be discussed even though both share the identical imaging
pipeline. I©ˆd prefer to remain conservative with
NDA©ˆs, you©ˆre free to say whatever you like of
course. That doesn©ˆt change the facts of how the products are
designed.
For those of you that want timely info about Lightroom
from those who©ˆve been working on it long before that name,
check out http://lightroom-news.com/
The basic
operating principles of this plug-in haven't changed
but that also
doesn't mean that new features might introduce new ways
of working
within the interface.
Not really and I©ˆm actually suggesting here
that one use the basic operating principles as the designers have
suggested! Adobe purchased and implemented a good deal of the
RSP©ˆs code into ACR and LR and made significant changes to the
imaging pipeline. I have dozens of emails from a very select alpha list (of
which I©ˆm pretty sure you©ˆre not privy to) that
discussed the evolution of how and WHY controls where placed where they
are, in addition to having compatibility with older versions of ACR. So,
your statement above is grossly simplified and not too accurate with
respect to ACR 4 or LR.
The processing order has been designed in a specific
fashion from day one. You can if you wish, bump saturation or Vibrance then
white balance or set clipping but I am suggesting that it©ˆs not
the most effective way to work with the products. Same could (and should)
be said for image corrections in Photoshop. By all means, alter saturation
then fix a color cast if you wish. Or sharpen then add noise reduction if
you wish. It would be useful if you would explain why such operations are
viable.
The fact is that the order that you make slider
adjustments is somewhat flexible in that nothing really
happens until
you click Open or Save!
Yes as I said, the order is flexible but it was
designed for a reason. Its not like going outside the order will make your
computer explode. However, I thought the point of this list was best
practices in using certain imaging products. If you©ˆd like to
discuss how to circumvent these concepts, and why its a good idea, go for
it. I©ˆm sure Mr. Knoll and Mr. Hamburg would like to know why as
well.
Certain slider adjustments have an
interdependent relationship however so that Curve
adjustments and
Exposure/Shadow/Brightness/Contrast affect the image
together.
Yes, Exposure/Recovery/Fill Light/Blacks/ (there is no
Shadow any more in this pane)/Brightness/Contrast affect the image together
and that©ˆs why they are lumped together in a single pane.
Highlights/Darks/Shadows/Black are in a different pane, and control tone in
a different order. There are tone controls that take place at the beginning
of the pipeline and those that take place after hence the grouping order
(which you don©ˆt have to follow but should when first working
with the product) that being start top down, left to right.
I find it amazing that by simply suggesting you follow
a recommended process, one discussed for years by the designers of the
product, a controversy is again generated on this list. I guess it depends
on who here makes the suggestions, not necessary the strength of the
recommendation nor where the recommendation originally came from.
As to the two Histograms, the output histogram is at
the end of the processing pipe and uses the sRGB response curve. The curves
histogram is prior to the tone curve but also uses an sRGB response curve.
If you start with Curves that will affect where
you start with the sliders -
the "tabs" do not force an order otherwise
when you back up to a
previous tab the image would revert to a previous
state. The is some
logic in the way the controls are laid out but the
interface is not
so fascist.
Agreed.
Everything you do in ACR affects everything else to a
certain degree
and the biggest problem with ACR is that often its hard
to figure out
the interactions.
Usually when you don©ˆt follow
it©ˆs design plan.
you can only see RGB numbers from the chosen output
profile ú no LAB, no
CMYK.
That©ˆs actually not the case for LR since
you are expected to export the data and unlike ACR, the numbers
(percentages) don©ˆt reflect this but rather reflect the internal
color space (aka Melissa RGB).
Given the limitations of the interface (and please,
this is obvious
regardless of features like Vibrance) Dan has suggested
taking a
conservative approach to the adjustments you apply in
ACR. ( Andrew,
before you jump on this, please READ Dan's book)
Let me preface by saying I©ˆve purchased
several of Dan©ˆs books but in this case, I see little reason to
since ACR in this context is grossly out of date and I©ˆm using a
version of Photoshop (for a good year and a half) not discussed in the book
due I suspect to poor timing on one of our parts <g>.
The idea of setting a raw converter at some imagined
zero setting to then use Photoshop to tone and color correct seems counter
productive for a number of reasons and appears to be useful for one who
doesn©ˆt fully understanding the toolset provided in the
converter. There are all kind of operations that simply can©ˆt be
done in a gamma encoded space as effectively as using a linear gamma
encoding. There©ˆs nothing in Photoshop remotely similar to
Vibrance or Fill Light or Highlight recovery. And no, Shadow/Highlight
isn©ˆt the same although I suspect some of the tools in LR will
migrate to Photoshop in the future. And this workflow is very slow,
doesn©ˆt allow an effective strategic way of applying the edits
to similar images non destructively.
It would be nice to get the scene referred high bit
data out of the converter from some work, however, there©ˆs no
setting according to Hamburg which guarantees that (At what point things
shift from scene referred to output referred is more or less in the eye of
the beholder. After all, if you set everything flat all the way through,
then there isn't really a transition point).
For most users, setting everything flat and working in
Photoshop to produce output referred imagery is a bit like using the little
bottle opener thingie on your old and much beloved Swiss Army knife to cut
down a tree instead of the new chain saw you have but can©ˆt
figure out how to start.
Fortunately, if
you've done your homework and tested your camera to
optimize your ACR
settings (at least visually) to your shooting style,
you shouldn't
have to do that much in ACR to get a reasonably good
image.
Nor Photoshop for that matter.
Andrew Rodney
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: Dan Margulis
Mon Feb 5, 2007 5:20 pm (PST)
Lee Varis writes,
Given the limitations of the interface (and please,
this is obvious
regardless of features like Vibrance) Dan has suggested
taking a
conservative approach to the adjustments you apply in
ACR. ( Andrew,
before you jump on this, please READ Dan's book) This
makes perfect
sense in a "one image at a time" workflow.
However, for many
photographers this is not practical when dealing with a
large volume
of images that have to be delivered to a client.
Fortunately, if
you've done your homework and tested your camera to
optimize your ACR
settings (at least visually) to your shooting style,
you shouldn't
have to do that much in ACR to get a reasonably good
image.
Quite right. I write only to point out that the book
clearly states that it is, as you say, only discussing "one image at a
time" workflows. Camera Raw has nice features for processing batches
of images but they are beyond the scope of what I write about.
Similarly, we all have occasions when we are unwilling
to spend time on images even when we know we might get better quality if we
took a few minutes more. In such cases, of course I have no issue with
someone who tries to get a fast result in Camera Raw and call it quits
there.
It does, however, beg the question: if saving time is
so important that quality compromises need to be made, why is the raw
format being used at all? With rare image-specific exceptions, essentially
anybody who is not a beginner will get better final results by shooting
JPEG and correcting in Photoshop than an expert can who shoots raw but is
not allowed to do any manipulation outside of the acquisition module. And
in less time, too. The idea of a raw module is to *empower* the
image-manipulation program, not replace it.
Dan Margulis
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Alan Klement"
Mon Feb 5, 2007 6:15 pm (PST)
With rare image-specific exceptions, essentially
anybody who is not a
beginner will get better final results by shooting JPEG
and correcting
in Photoshop than an expert can who shoots raw but is
not allowed to
do any manipulation outside of the acquisition module.
I'm no ass-kisser to Dan, and this is a powerful and
correct statement. I work as a retoucher and digital tech. When I meet
other "professional" techs they balk at my insistance to
compensate for linear exposure- the same with some photographers who demand
the exposure be a certain way.
Then it comes to me as a retoucher and I'm left with a
RAW file that has SERIOUS noise and banding in the transistions and shadows
and I'm told to take it out. Why bother shooting RAW if your not going to
expose correctly. Otherwise shoot jpeg and get the same final result.
Batch RAW processing seems so silly. I have friends who
are wedding photographers and they all shoot jpeg, and if need be, they can
make sufficient corrections in Photoshop for the rare occasions that some
tweaking is made. They have beautiful results as well.
Alan Klement
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "MARK SEGAL"
Mon Feb 5, 2007 8:55 pm (PST)
This was correct without exception until recently, but
with the advent pf Lightroom and the new ACR it is much less clear-cut.
These programs are very powerful and feature-rich. While they are not
intended to replace Photoshop, they are specifically aimed at a
photographic workflow, such that a high percentage of what most
photographers need most of the time can be accomplished within them.
Recognized professionals have successfully conducted whole photoshoots
including a wide variety of images from start to finish in Lightroom. The
new ACR is very similar to the Develop Module in Lightroom.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Lee Varis"
Mon Feb 5, 2007 9:39 pm (PST)
On Feb 5, 2007, at 4:52 PM, Dan Margulis wrote:
It does, however, beg the question: if saving time is
so important
that quality compromises need to be made, why is the
raw format being
used at all?
While it is not so important for many photographers the
RAW format has special value for me because it allows me to optimize my
images in ways the the camera manufacturer didn't imagine when they hard-
wired the rendering algorithms for the in-camera Jpegs. I routinely expose
to the brink of oversaturation of the chip and adjust the rendering in ACR
to keep as much separation in midtone, highlight and shadow values as
possible. This also keeps shadow values well above the noise floor of the
chip so I get much better detail in shadow values. This, of course, makes
precise exposure control mandatory – something I take special pride
in doing as a matter of course for professional work. I can bias the color
rendering to compensate for the tendency of digital capture to over
emphasize red in skin tones. I can customize the way the data is rendered
to specifically address the subject, lighting and camera body I'm using.
This is more than the camera manufacturer can possibly do because they must
set their renderings for the most common generic photo capturing situation
and they must try to protect the less sophisticated user from over exposure
and aim for a generic "pleasing" result rather than a
specifically optimized result. So, for me at least, its not about saving
time so much as it is about optimizing quality.
Jpeg rendering is most often too contrasty and too
saturated to offer the best possible starting place for image development.
RAW offers a better starting point if you reset your defaults to give you
access to the tonal range that is possible from the RAW data – You
have to expose properly to do this as Alan laments:
Then it comes to me as a retoucher and I'm left with a
RAW file that
has SERIOUS noise and banding in the transistions and
shadows and I'm
told to take it out. Why bother shooting RAW if your
not going to
expose correctly.
This is the biggest advantage of RAW - being able to
figure out the optimum exposure index for the specific chip in a particular
camera body based on zero-state or linear post-process controls - you can
then process flat for maximum tonal range and adjust to optimize the image
in Photoshop OR you can pre-bake your settings to give you as close to a
finished look as possible in ACR for volume commercial image delivery. This
is a flexibility that I would not give up unless I needed a super fast
turnaround time – in that case I'd happily shoot Jpegs! If you don't
need to hand off the files right out of your camera, like you might for
fast breaking news photos, why wouldn't you opt for less noise and more
detail in your shadows – more shape in RGB channels for blends
– no Jpeg artifacts in A & B channels for blending or the
opportunity to "recover" more tone in highlight values for
blends.
While RAW processing can be advantageous for seriously
bad image files that need heroic rescue efforts, the real value lies in
squeezing the maximum quality out of your image captures by carefully
optimizing your exposures to match your RAW processing options.
regards,
Lee Varis
President, LADIG
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Mark Segal"
Tue Feb 6, 2007 8:06 am (PST)
Lee,
Thanks for spelling all this out so fully. It is all
correct (with new tools more so than ever) and underlies why I posted a
shorthand reply on this matter last night.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Alan Klement"
Tue Feb 6, 2007 8:07 am (PST)
Disclaimer: I am only speaking with regard to offset
printing images. Go to a Barnes and Noble right now and look at the cover
of Vive and Vegas to illustrate my point. I worked on these image. (shot in
JPEG)
I can guarantee you that most of the time RAW + LR/ACR
with very
little effort will produce much better photographs than
a JPEG baked
in-camera - even from a Canon 1Ds.
The point I saw Dan making, and I agreed with, was the
issue regarding batch RAW processing and only doing "minor"
tweeks in LR or ACR. I have retouched several images shot in JPEG that
ended up on magazine covers and they looked great. (hint: any image you see
shot of Miss Teen USA, Miss USA and Miss Universe, or YRB magazine and
others...)
It suited these photographers workflows to shoot JPEG.
This is the biggest advantage of RAW - being able to
figure out the
optimum exposure index for the specific chip in a
particular camera
body based on zero-state or linear post-process
controls - you can
then process flat for maximum tonal range and adjust to
optimize the
image in Photoshop OR you can pre-bake your settings to
give you as
close to a finished look as possible in ACR for volume
commercial
image delivery.
I'm not speaking with cynicism, but why go through all
this effort. I just don't get it- if it's going to end up in a catalouge
(the only situation I could think of where batch raw processing would be
used).
I've actually worked in these studios, the photographer
shot jpegs and handed the images off to retouchers who had less than 10
minutes to fix an image then we went on to the next.
Now when I tech on L'oreal, Vogue, Oil of Olay,Hugo
Boss, Dove- whatever. We shoot RAW and then it coems down to one image and
I squeese the hell out of that RAW file to get a nice image.
BUT I'll guarantee you. If you put two magazine tear
sheets of that Hugo Boss ad shot in RAW next to that Miss Universe image
shot in JPEG image you wont see much of a difference at all.
Come on guys, I don't want to be a smart ass or
arrogant prick, and I respect your knowledge, but can we stop with the
academic talk. This is what I've learned from Dan's work and why I love it.
Lets get real world here...images that are going to offset printing and end
up on some paper that for the most part is translucent.
Alan Klement
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Ron Kelly"
Tue Feb 6, 2007 8:47 am (PST)
Lee:
No question here. Extra effort yields results.
However, if you're not tweaking every image
individually, which someone who takes special pride *is* doing, the
difference between shooting RAW and jpegs is lost. Batch processing of RAW
files only makes sense if the images are all very similar.
I don't think Dan is arguing against the benefits of
shooting RAW and the difference it can make. He's simply pointing out that
it's a silly workflow when all you are going to do is batch process the lot
of everything according to the programs defaults, or some other static
values.
In my work I shift back and forth between RAW and jpeg,
and of course RAW+jpeg when situations allow. If you aren't shooting high
volumes you can be more picky, but as the number of exposures processed
adds up you find yourself looking at the beach ball more and more.
When that happens, I like to look in on the color
theory list and see the latest tilt.
Cheers,
Ron Kelly
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: Dan Margulis
Tue Feb 6, 2007 9:18 am (PST)
Alan Klement writes (and Ron Kelly similarly),
The point I saw Dan making, and I agreed with, was the
issue regarding
batch RAW processing and only doing "minor"
tweeks in LR or ACR. I
have retouched several images shot in JPEG that ended
up on magazine
covers and they looked great.
We need to back off for a bit because I think Lee's
explanation changed the ground rules. As I understood what he said he is
deliberately shooting in a way that would produce a bad JPEG, knowing that
he has Camera Raw as a safety net. There's a lot of potential merit to that
approach: digital cameras are a marvelous step forward, but they have a
couple of serious problems, most pressingly, they don't handle underexposed
(overly dark) images as well as film does--digital cameras, even the best
ones, are very noisy under poor lighting conditions. It can make getting a
good result very difficult whereas a similarly underxposed piece of film
could be corrected easily if drum-scanned.
There is, however, no similar difficulty that I'm aware
of in correcting a digicam capture that's *over*exposed (too light) unless
detail has actually been blown out. From that, it seems logical that one
might intentionally shoot in that fashion, and it sounds like that is what
Lee is doing. If he says that if he were to shoot JPEGs using these same
exposure settings and hand them to a client the response would be that the
client would think he was an incompetent hack, then I withdraw my
comments--in that case, there might be sufficient damage in the JPEG that
it would be difficult to recover.
For the more common type of exposure, however, if the
person refuses to exit Camera Raw at all, that means he has no access to
channel blending, he won't have channel-by-channel curves, he won't have
the ability to select, or to retouch, or to use LAB or CMYK, or to sharpen
in a sensible way, or to correct casts that aren't uniform. In short, he's
racing on a tricycle against the jet aircraft of Photoshop proper. So
anyone who (excepting Lee and people who shoot in this way) says they will
*never* exit Camera Raw is saying that time is more important than quality.
If so, it's a better use of time on the whole to just shoot JPEGs and use
the time saved in capturing, acquiring and editing in Camera Raw to hack at
the file in Photoshop.
Dan Margulis
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "MARK SEGAL"
Tue Feb 6, 2007 9:18 am (PST)
From: Alan Klement
Disclaimer: I am only speaking with regard to offset
printing images..
Thanks for the disclaimer. My frame of reference is
artistic photographs destined for an inkjet printer and thereafter to be
put in a collection. Obviously this could make for differences in workflow
considerations. In the context of fine art photography comparing the
results of JPEGs versus properly processed RAW images as reproduced by an
offset printer on magazine paper just doesn't cut it. And that point is not
academic - I shoot JPEG and RAW in parallel and by the time I finish with a
RAW file generally speaking there is no comparison. Lee Varis got it right.
I have no experience judging this issue from the perspective of magazine
reproductions so I won't comment further on that.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Andrew Rodney"
Tue Feb 6, 2007 9:19 am (PST)
On 2/5/07 5:52 PM, Dan Margulis wrote:
Similarly, we all have occasions when we are unwilling
to spend time on
images even when we know we might get better quality if
we took a few minutes
more. In such cases, of course I have no issue with
someone who tries to get a
fast result in Camera Raw and call it quits there.
It does, however, beg the question: if saving time is
so important that
quality compromises need to be made, why is the raw
format being used at all?
Compromises? Nope. There©ˆs way more to this
than speed. That©ˆs icing on the cake. You apply ALL metadata
edits, (which I would argue provide more control over image rendering), at
once, the result being superior data (numbers) thanks on linear encoding
high-bit wide gamut RGB compared to doing this on a rendered flat sloppy
raw conversion brought into Photoshop. Better and faster. Nothing stops you
from additional tweening in Photoshop for the fine pixel polishing and
I©ˆd add, soft proofing, conversions, and output sharpening!
Raw processing is image creation, not image correction!
Those who create the images are those who should have the skills to render
the image as the wish (even if that means producing a color cast someone
else thinks they need to remove later in Photoshop).
With rare image-specific exceptions, essentially
anybody who is not a beginner
will get better final results by shooting JPEG and
correcting in Photoshop
than an expert can who shoots raw but is not allowed to
do any manipulation
outside of the acquisition module. And in less time,
too.
Another challenge! You©ˆre on Dan. In front
of an audience. Next Photoshop World? PMA? PPE?
As to why the use of raw, you need to talk to more
people who make images for a living.
We have to get you a gig at PPE so you can meet some
photographers.
What other raw converters besides the old ACR have you
used?
And now for something completely different. I asked
Brian of Raw Developer his take on the Lab/RGB/Lab conversion debate. This
isn©ˆt marketing, it©ˆs the guy who wrote the product*:
At 8 bits/channel there probably would be some rounding
errors in the
RGB to LAB and back to RGB round trip. I haven't
personally done any
technical study of whether this is really significant
or not. On
visual inspection in the past when I worked more often
at 8
bits/channel I used to go to LAB for some operations
and never ran
into any obvious problems that I was aware of from a
visual
standpoint anyway. I probably wouldn't as a general
practice
recommend say in Photoshop at 8 bits/channel repeatedly
going back
and forth between LAB and RGB many times, but say a
single conversion
to LAB for some curves, sharpening or noise reduction
and then back
to RGB I don't think would result in significant or
noticeable visual
degradation of the image even at 8 bits/channel.
* I have no association with this product and in fact
paid for it in full (geez, it©ˆs only $99). I think
it©ˆs a very good raw converter as far as quality of rendering!
There©ˆs not much in the way of workflow. IOW, if you are a one
image at a time raw user, check it out. Brain, as you can see is very
accessible too.
http:
//www.iridientdigital.com/products/rawdeveloper.html
On 2/5/07 6:50 PM, "Alan Klement" wrote:
Why bother shooting RAW if your not going to
expose correctly. Otherwise shoot jpeg and get the same
final result.
This is different from incorrect JPEG exposure? I
don©ˆt understand your point about raw. If anything, you have
more exposure compensation but if you haven©ˆt a clue how to
exposure for it or operate a camera in a professional way, anything is
possible. Is this like dumb people who screw things up with profiles
because they don©ˆt understand what they©ˆre doing?
Seriously, there are far more ways to hose a JPEG than a raw file if you
really want to put stupid people behind a camera. You get many white
balance issues with your JPEGs?
You are always shooting raw, even when you end up with
a JPEG! That you are tossing away the raw in no way makes proper capture
less an issue respect to being sloppy.
What would be useful, and what will happen, is the
ability to perfectly match the initial rendering of a raw file in a
converter to that of the camera generated JPEG. The camera manufacturers
know a LOT about color rendering! They've been doing it a very long time
(like 100 years). This software stuff is kind of new. However, there are
still all kinds of automatic assumptions being made by the circuits in
those cameras producing the JPEG from what IS raw data! You have no control
over it when things go the way you don't want them to go.
I am however curious about the global color and tone
issues you get with both rendered or raw images, if any. There's plenty of
work for retouchers but global tone and color should happen at the
rendering stage. Minor dust busting (clone and healing) too (remember,
expect for dust on the sensor, no more hours of spotting dirt out of high
rez film scans).
Wouldn't you rather move past all that global color and
tone work from the get-go and get onto the serious Photoshop retouching?
They have beautiful results as well.
No question. I work with lots of very good, very high
paid wedding photographers. And those friends you mention above have
compared these JPEGs to the same images processed in raw? If not, how can
we compare the workflows and the results? If so, what was the workflow and
was it properly maintained?
Too many blanket statements. Let's do the science. I
did a Raw Iron Chef shootout at PPE last year. Next year I think it needs
to be Raw Iron Chef versus Render Iron Chef and we get Dan to NY.
On 2/5/07 10:32 PM, "Lee Varis" wrote:
While RAW processing can be advantageous for seriously
bad image
files that need heroic rescue efforts, the real value
lies in
squeezing the maximum quality out of your image
captures by carefully
optimizing your exposures to match your RAW processing
options.
It sounds like we are in agreement and in this case,
strong disagreement on Dan's take that (as I read it) raw processing is for
"occasions when we are unwilling to spend time on images even when we
know we might get better quality." Raw processing is ALL about
quality. Speed is an added benefit.
Andrew Rodney
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Mark Segal"
Tue Feb 6, 2007 10:28 am (PST)
For the record, I never had in the back of my mind a
notion that one would "never" exit Camera Raw. it is not a matter
of "either" "or", but rather when and why to use each.
In fact, I mentioned in a previous post that neither Lightroom nor the new
ACR were ever intended to completely displace Photoshop. My point is that
these new tools are taking us every closer to self-contained powerful
workflows operating on metadata that will save many photographers alot of
time and trouble in Photoshop. Inevitably, and intentionally, trips to
Photoshop will remain necessary for numerous reasons (e.g. for now using
Photokit Sharpener, making final pre-print adjustments in Soft Proof mode)
- I for one would not do without it, but I recognize and appreciate how
much the new tools are displacing operations in Photoshop with easier
manoeuvres that are producing great results. My perception is that over
time more users will increasingly appreciate that the names of the tools on
the tricycle and the jet aircraft change names depending on the
destination.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Alan Klement"
Tue Feb 6, 2007 11:30 am (PST)
Thanks for the disclaimer.
Good call Mark, and I will use your words (with a
slight modification) to bring my POV into perspective...
I have no experience judging this issue from the
perspective of "artistic photographs destined for an inkjet printer
and thereafter to be put in a collection" so I won't comment further
on that.
:)
Andy, as I think Mark and Dan pointed out: claification
is paramount to having an effective discorse.
When I say "they shoot JPEG" I mean they only
save their files on their CF card as JPEGS.
This is different from incorrect JPEG exposure? I
don©ˆt understand
your point about raw
(you know this but I'm clairifing my point)
When working on set as a tech on a big job, we capture
in RAW, but the aquisition software ( C1, LeafCapture...) will display a
JPEG preview of the capture. If one exposes for linear capture, this jpeg
will look overexposed, unless you apply a curve to the preview that makes
this preview look correct. We do this because if the art director or
photographer sees this they will scream "what are you doing it looks
like crap!"
In this case we are "shooting RAW".
2nd Scenerio is my catalouge shooting experinces. I've
been part of workflows that ended up in many catalouges. In this case, the
jpeg that pops on the camera's LCD or computer monitor is what we go with,
and don't save the RAW. There is no time to mess with RAW- because we have
200 dresses to shoot in 2 days or 100 peices of jewelery in one day. The
budget will not allow for any "real" retouching and only one day
rate for the photographer, tech and retoucher.
We keep in mind the final output as I mentioned before
"magazines with translucent paper"
In this case we are "shooting JPEG"
I work with lots of very good, very high paid wedding
photographers. And those friends you mention above have
compared these
JPEGs to the same images processed in raw?
Not that I'm aware of, but why? They get brilliant
results with their JPEG workflow, and again, with output in mind, this is
gonna be printed by Joe Shmo on a Fugi-Lamda-Lightjet-whatever printer at
5x7 or MAYBE 2-3 8x10s and in an sRGB or colormatch color space.
my head hurts...
Alan Klement
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: Dan Margulis
Tue Feb 6, 2007 11:32 am (PST)
Mark Segal writes:
For the record, I never had in the back of my mind a
notion that one would
"never" exit Camera Raw. it is not a matter
of "either" "or", but rather when
and why to use each.
Then, I think there has been a major misunderstanding,
because the quote to which you were directly responding said:
"With rare image-specific exceptions, essentially
anybody who is not a beginner will get better final results by
shooting JPEG and correcting in Photoshop than an expert can who
shoots raw BUT IS NOT ALLOWED TO DO ANY MANIPULATION OUTSIDE OF THE
ACQUISITION MODULE. [emphasis added]
I trust you will agree that the statement clearly and
unambiguously refers ONLY to persons who refuse to do any
manipulation in Photoshop at all, and that it does not say or imply
anything about people who work in Raw first and *then* work in
Photoshop. (And I backed off it somewhat, too, in the light of Lee's
response.) PP5E states explicitly that I think are occasions when
best results are only possible through the use of Camera Raw or
similar module.
Dan Margulis
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Lee Varis"
Tue Feb 6, 2007 7:14 pm (PST)
On Feb 6, 2007, at 9:15 AM, Dan Margulis wrote:
We need to back off for a bit because I think Lee's
explanation changed the
ground rules. As I understood what he said he is
deliberately shooting in a way
that would produce a bad JPEG, knowing that he has
Camera Raw as a safety
net.
Correct, except I don't consider Camera Raw a safety
net - just a better way to setup the image. To fully take advantage of RAW
processing you have to expose even more carefully than you do normally
because you are flirting with overexposure – if you go to far there's
no coming back – no safety net there!
The Jpeg clips values at both ends of the tonal range
and I'm "placing" the values at the upper limit of the captured
data. In some cases this highlight info would be clipped to white in the
jpeg so shooting Jpegs this way would not work! RAW processing is not a way
to protect against bad exposure so much as a new way to handle digital
capture.
If you test for this new setup and save new default
renderings you can end up with better images but there's no automatic way
to handle every image the same way so you do have to spend some time post
capture to setup your processing and many, in a time = money workflow may
not find enough value in pursuing RAW.
Beginners may find RAW to be a "safety net"
to protect against mistakes but Professionals will use RAW to squeeze the
best possible quality out of an image by carefully placing scene values
into the best range of the captured data and setting the rendering or
processing for a more ideal value structure – very much like the old
B +W negative strategy of "expose for the highlights and process for
the shadows". I have an old ACR tutorial for the calibration procedure
and I'm currently working on an updated version to handle Lightroom/ACR 4.
regards,
Lee Varis
President, LADIG
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Andrew Rodney"
Tue Feb 6, 2007 7:17 pm (PST)
On 2/6/07 10:15 AM, Dan Margulis wrote:
We need to back off for a bit because I think Lee's
explanation changed the
ground rules. As I understood what he said he is
deliberately shooting in a
way that would produce a bad JPEG, knowing that he has
Camera Raw as a safety
net.
No, that©ˆs not necessarily correct and there
have been no ground rules as usual. There©ˆs always a Raw file
and proper exposure is always a factor. The JPEG is an after thought.
It©ˆs only based, can only be based, on the initial Raw capture.
In film, which isn©ˆt linear encoded but has a H&D curve, we
expose for the shadows, develop for the highlights. In raw (or JPEG) we
expose for the highlight. It©ˆs as simple as that.
There©ˆs a huge misunderstanding by some on
this list about how a digital camera produces data. It©ˆs ALWAYS
raw. You can decide to toss it and let the camera bake the JPEG or you can
do it yourself (or both). But what Lee correctly points out is you need to
know the true ISO (chip sensitivity) and you have to expose properly for
the scene you want to capture which IS an artistic expression. We have
cameras that have a good six stops of dynamic range. If the scene exceeds
this range, we have to decide where to place the exposure to capture those
six stops.
A primer or digital capture exposure:
http:
//www.luminous-landscape.com/tutorials/expose-right.shtml
This isn't over exposure, its correct exposure!
There's a lot of potential merit to that approach:
digital cameras are a
marvelous step forward, but they have a couple of
serious problems, most
pressingly, they don't handle underexposed (overly
dark) images as well as
film does--digital cameras, even the best ones, are
very noisy under poor lighting
conditions. It can make getting a good result very
difficult whereas a
similarly underxposed piece of film could be corrected
easily if drum-scanned.
I think you need to let us know what digital cameras
you©ˆre referring to because in the case of my Canon 5D, the
images are spectacular with respect to noise even at 3200 ISO and simply
blow away film at that ISO in terms of noise. What camera(s) are you basing
this upon? I'm sure the list would like to know this. If the noise does bug
you, then check out Noiseware which will reduce almost all the noise while
maintain amazing fine detail.
When you accept my challenge, lets shoot some film (neg
or chrome, your call) at 1600 ISO, I'll shot the same scene at 3200 ISO
digital and the audience can decide if film did a better or inferior job
with respect to noise. We can dig up an old drum scanner, no problem.
Since I'm being ignored is anyone else interested in
such a real world challenge and if so, can you ask when proof will be
presented to back up the claims made here? I'm willing and ready. My
suggestion is PhotoPlus in NY (largest photo show in the country) in
October. I'm pretty sure I can get this on the agenda unless certain
parties vacillates past April when the show people start organizing the
seminars.
There is, however, no similar difficulty that I'm aware
of in correcting a
digicam capture that's *over*exposed (too light) unless
detail has actually
been blown out.
No, you can easily blow out highlights due to the raw
to JPEG conversion, which you have no control over, and then regain up to 1
stop back IF you use the raw file in a good converter like ACR or LR.
For the more common type of exposure...
As a trained photographer, can you explain to the list
what a 'common type' of exposure is? There©ˆs correct exposure,
based on the capture device (film or digital) then there are varying
degrees of incorrect exposure. And since we have to capture a potentially
huge scene dynamic range using a device with a fixed capture dynamic range,
the exposure is right when the person creating the image decides what they
want and where to place these six stops in relations to the scene. I think
you need to understand the concepts designed by Ansel Adams
(pre-visualization and the zone system) when discussing
Œcorrect©ˆ exposure. One of the roles of an image creator we
refer to as a photographers is not only to render the image as they seem
fit but prior to this, placing the limited dynamic range of any scene into
that which the camera (film or sensor) can realize. With that in mind, it
would be useful if you would explain what you mean by 'common exposure'.
however, if the person refuses to exit
Camera Raw at all, that means he has no access to
channel blending, he won't
have channel-by-channel curves, he won't have the
ability to select, or to
retouch, or to use LAB or CMYK, or to sharpen in a
sensible way, or to correct
casts that aren't uniform.
No one is proposing this. What some of us are proposing
is using the right tool for the right job. You HAVE to convert scene
referred data into output referred data and build a pixel based color file
before Photoshop can enter the picture. As Lee and Mark have tried to point
out, the toolset and quality is vastly superior (and I am willing to prove
it to you in front of a live audience) compared to doing this later in
Photoshop. The math is undeniable but further, the people who have a better
understanding of the tools and are creating images are saying this here as
well. And it has nothing to do with polishing one or dozens of images in a
converter.
Tell you what, even if I take 2x times longer to
produce a preferred rendering then you, I can apply that to similar images
far faster than you can drag and drop adjustment layers on the same number
of files. Select, copy/paste metadata settings. Done.
Example of this in LR:
http:
//pictureflow.fileburst.com/_Tutorials/Photoshop_LR/06/index.html
In short, he's racing on a tricycle against the jet
aircraft of Photoshop proper.
I think in this context, some are so unfamiliar with
one mode of image processing, the analogy falls very flat.
But again, I'm willing to prove to you that ACR/LR for
the tasks it's designed for is the jet and not Photoshop and that there ARE
tools and processes where the opposite is true. But making simple blanket
statements rather than proving them is par for the course I guess.
So anyone who (excepting Lee and people who shoot
in this way) says they will *never* exit Camera Raw is
saying that time is
more important than quality.
No one is saying this. While the topic is photography,
slanting this as black or white is counterproductive. Its about using the
tools properly and if you©ˆre going to be real sloppy with
exposure then raw rendering or JPEG will suffer and begs the question, why
did this sloppiness happen in the first place?
On 2/6/07 12:13 PM, "Alan Klement" wrote:
When working on set as a tech on a big job, we capture
in RAW, but the
aquisition software ( C1, LeafCapture...) will display
a JPEG preview
of the capture. If one exposes for linear capture, this
jpeg will
look overexposed, unless you apply a curve to the
preview that makes
this preview look correct.
It shouldn©ˆt look like crap but there most
certainly is a disconnect between the JPEGs and the raws depending on the
neutral raw rendering. And yes, the Histogram and info we see on many
DSLR©ˆs isn©ˆt based on the raw data but the in camera
raw rendering which presents a bit of a problem for the shooter. I will say
with the 5D once I nailed the ISO and exposure, the JPEGs on the back of
that LCD don©ˆt look bad but I am only using them to check focus.
It would be nice if the Leaf software would
automatically apply a tone curve to mitigate this crappy looking JPEG.
Not that I'm aware of, but why? They get brilliant
results with their
JPEG workflow, and again, with output in mind, this is
gonna be
printed by Joe Shmo on a Fugi-Lamda-Lightjet-whatever
printer at 5x7
or MAYBE 2-3 8x10s and in an sRGB or colormatch color
space.
I©ˆd be the first to agree that if the job is
500 widgets on a white bkgnd, shooting raw under a tight deadline is
probably overkill if the final is going 2x2 in a parts catalog and
that©ˆs that. A wedding? A different story. And again, if the
workflows are not compared, we can©ˆt place a metric on
Œbrilliant results©ˆ or what raw would bring to the party
(and maybe take away). Another reason I suggested a challenge which Dan
will ignore since I posted it but, I'm totally serious about doing this so
that at the very least, we can see the benefits and warts of both
approaches.
Heck, comparing a 1.0 product to a version 10.0 product
should be a slam dunk.
Andrew Rodney
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Mark Segal"
Tue Feb 6, 2007 7:18 pm (PST)
Dan, I read that. The purpose of my post really wasn't
to take issue with anyone espousing any particular philosophy (or dogma)
for editing images. But I used myself as an example because I don't know
the universe of users out there. So I don't think we're disagreeing about
anything fundamental. I'm simply emphasizing the rapid evolution of new
tools, which call forth a certain amount of rethinking about some aspects
of workflow. I think this whole discussion started because some of the
comments in this thread - I forget now by who - seemed to undervalue the
potential contribution of these tools.
Just as a small example of how I see things heading,
have you tried the Vibrance slider in ACR-CS3 beta and compared it with
steepening the "a" and "b" curves in Lab? Vibrance can
do a bang-up job of improving colour contrast in a jiffy. I think we'll see
a growing number of people who will find that with some - perhaps even many
- images, this one little non-destructive adjustment to some meta-data in
Camera Raw replaces a trip back and forth to Lab, carefully moving the
curves, placing the Lab adjustment on a separate layer to preserve
reversible editing for reimportation into RGB, etc. But that doesn't mean
this use of Lab is relegated to the waste-bin of history - it just means
there is now an easier and effective option that may do the trick alot of
the time.
I'm hugely impressed with the promise of what Thomas
Knoll and the Adobe team are producing - and from the experience I'm
gathering using it quite intensively, suggesting that we're into a quantum
leap in editing technology we should all appreciate.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Lee Varis"
Wed Feb 7, 2007 5:20 am (PST)
On Feb 6, 2007, at 7:42 AM, Alan Klement wrote:
Come on guys, I don't want to be a smart ass or
arrogant prick, and I
respect your knowledge, but can we stop with the
academic talk. This
is what I've learned from Dan's work and why I love it.
Lets get real
world here...images that are going to offset printing
and end up on
some paper that for the most part is translucent.
Unfortunately for most photographers doing high-end
work their client is an art director or a designer with a computer and a
copy of photoshop and when they get the digital file from the photographer
they look at it on screen, zoom in and out and evaluate it compared to
other high-end photographers work – on screen. They don't appreciate
that, for the most part, all this extra quality is completely lost in the
offset litho print! To stay in the game and be competitive in an extremely
competitive environment you have to deliver that little bit extra!
Now... if I was shooting high volume catalog, weddings,
sports or news, I'd shoot Jpegs because the benefit/compensation/time
equation just doesn't pan out!
regards,
Lee Varis
President, LADIG
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "MARK SEGAL"
Wed Feb 7, 2007 5:20 am (PST)
Lee,
Once you have this up-date ready I would really
appreciate seeing it. In fact, if you have a link to the old one that could
still be of interest too.
Mark Segal
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Hoffner, Randall N"
Wed Feb 7, 2007 11:08 am (PST)
While I think his conclusions are correct, the Luminous
Landscape piece doesn’t really explain what’s going on at all,
or why it’s going on. It’s pretty glib, and the details are not
there. But then, he isn’t a mathematician or a scientist, is he? I
think the explanation in Bruce Fraser’s ACR book is more complete.
One of these days, I am going to have to write a detailed explanation of
exposure versus bits myself, as it is one of those things that I have to
think about and re-comprehend every time I consider it.
Regarding the film versus digital challenge, I would be
very interested in seeing the results of such an effort. My own experience
shooting a low-light picture with my Canon 20D at ISO 1600 (2005) versus
shots I took on film in the Ginza at night (1991), or in a French cathedral
in daylight (1980’s sometime) using I don’t know what ISO film
(no metadata!) bring me to the same conclusion as Andrew made I can
brighten the 20D shot up nicely without noticing very much noise,
particularly when printing it, as opposed to viewing it on an LCD screen.
The film shots – not so much! And certainly back in the day nobody in
their right mind would consider using ISO 1600 film let alone ISO 3200
film, unless out of dire necessity!
Randy Hoffner
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Andrew Rodney"
Wed Feb 7, 2007 1:30 pm (PST)
On 2/7/07 11:39 AM, "Hoffner, Randall N"
wrote:
While I think his conclusions are correct, the Luminous
Landscape piece
doesn`t really explain what`s going on at all, or why
it`s going on. It`s
pretty glib, and the details are not there. But then,
he isn`t a mathematician
or a scientist, is he?
Michael no, Thomas yes of course.
So here's the deal. You've got a sensor that is a
photon counter and produces linear encoded data. If you have a six stop
dynamic range from highlight to shadow, using a 12-bit capture, that
results in 4096 steps from end to end. Half that data (2048 bits) describe
that first stop of highlight data while only 16-bits describe the last stop
of shadow data. And the shadows are where all the noise lives. If you
expose properly (to the right), for the highlights, you can place the best
16-bits in that stop of shadow data but if you under expose, that results
in fewer useful bits (and more noise).
I think the explanation in Bruce Fraser`s ACR book is
more complete. One of
these days, I am going to have to write a detailed
explanation of exposure
versus bits myself, as it is one of those things that I
have to think about
and re-comprehend every time I consider it.
There's also this:
http://www.ppmag.com/reviews/200612_rodneycm.pdf
Regarding the film versus digital challenge, I would be
very interested in
seeing the results of such an effort.
We continue to await a reply from Dan. Of course,
anyone else could pick up the touch and be the Render Raw Chef but that
wouldn't be as fun.
My own experience shooting a low-light picture with my
Canon 20D at ISO 1600
(2005) versus shots I took on film in the Ginza at
night (1991), or in a
French cathedral in daylight (1980`s sometime) using I
don`t know what ISO
film (no metadata!) bring me to the same conclusion as
Andrew made I can
brighten the 20D shot up nicely without noticing very
much noise, particularly
when printing it, as opposed to viewing it on an LCD
screen.
And the 5D chip is even better!
Andrew Rodney
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Richard Wagner"
Wed Feb 7, 2007 2:39 pm (PST)
More properly, "Half that data (2048 levels, or
steps) describe that first stop of highlight data while only 16
levels or steps describe the last stop of shadow data."
A bit is a binary placeholder - with a value of zero or
one. It is not equivalent to a level or step.
--Rich Wagner
"There are 10 kinds of people in the world, those
who understand
binary and those who don't."
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Hoffner, Randall N"
Wed Feb 7, 2007 4:11 pm (PST)
Okay, to really comprehend this, let's not start out
describing light levels in terms of f/stops, at first (f/numbers are simply
ratios, aren't they?).
On the top end of the scale, there is a particular
light intensity (a particular number of photons per unit area) that is the
highest light level that can be accommodated by a sensor, and at the bottom
end of the scale, there is zero light level. This scale of light intensity
is linear and analog. When we sample and digitize, a sample is taken, and
this sample is assigned a quantization number based on its intensity. If a
sample is quantized at 12 bits, the quantization number can be any number
between 0 and 2 to the 12th power, or 4096. If there is zero light present
on the sensor, the quantization number is zero. If the maximum value of
light is present, the quantization number is 4096. If exactly half the
maximum value of light is present, the quantization number is 2048 (11
bits). As each sample has to be assigned a specific quantization number
(can't fall in the cracks between numbers), the higher the number of
quantization levels (bits) available, the closer any given sample is likely
to be to a quantization number, so the smoother the "edges", as
it were (the less quantization noise is generated). Quantization noise is
essentially the difference between the actual value of a sample and the
closest quantization number to it. Quantization noise decreases as the
number of quantization levels increases.
As stated, if the maximum possible value of light
intensity is present, it is quantized at 4096. (If we go over the maximum,
this is also quantized at 4096, which is also known as a brick-wall
clipper, or as a blown-out highlight). If we reduce the light value by
exactly half (a one-stop reduction), the quantization number is 2048 (11
bits). If we reduce the light value by half again (another one-stop
reduction), the quantization number is 1024 (10 bits). So if we have a
six-stop range down from 4096, we go as follows:
Light Quantization
Intensity Number
100% 4096 maximum level 12 bits
50% 2048 1 stop reduction 11 bits
25% 1024 2 stops
10 bits
12.5% 512 3 stops
9 bits
6.25% 256 4 stops
8 bits
3.125% 128 5 stops
7 bits
1.5625% 64 6 stops
6 bits
So as we see, while the light levels from maximum to
one f/stop below maximum have a range of 4096 quantization numbers to which
they may be assigned, while the light levels corresponding to the range
from 5-6 stops down from maximum only gets 64 bits of quantization range
(between 128 and 64). The light levels between 1.5625 % and 0 are below the
usable range. We see that this is the range between 3.125% and 1.5625% of
maximum light levels, so these are low light levels. Less signal with the
same noise level translates to a lower signal-to-noise ratio. But the lower
the light level, the less the human visual system notices the detail, or
the noise that is present.
The bottom line here is that in order to optimize your
SNR, you should use all the quantization levels available to you. But don't
despair if you have shadows where the light level is low, because the noise
won't kill you.
Randy Hoffner
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "dbernaerdt"
Wed Feb 7, 2007 4:11 pm (PST)
Andrew,
At risk of beating a horse that is already down...
While the math all sounds good, let's have a closer
look at the "expose to the right" advice.
I get the opportunity to hire photographers outside my
market roughly a half dozen times a year, work with supplied images daily,
and create original photography daily. What I see is either a trend that
photographers are more sloppy than in the past and/or perhaps more more
people are calling themselves a photographer without a clear understanding
of the tools they are using. I even hear/read advice to "throw out
your light meter" now that the industry is mostly based around digital
capture. Consistently I see at least one channel blown out in the
highlights of many images I receive.
Lee Varis had some excellent advice to test your camera
to determine an Exposure Index. Why? (I just shot a series of test images
to confirm what I saw in the past - shot on a Nikon D2x if this matters to
anyone.)
The composite histogram on the camera's display will
change depending on whether sRGB or AdobeRGB is selected in the camera. It
also changes if the tone curve is changed. It changes again depending on
the white balance setting on the camera.
The camera's histogram does not match the one I see in
ACR with it on its default "out of the box" settings, using Auto
check boxes or zeroing the settings. Doesn't match in Capture One (C1)
either. Performing a custom white balance in the raw convertor changes it
again. (Keep in mind that ACR and C1 ignore all but the WB setting on the
camera.)
So how are we supposed to "expose to the
right" with precision? According to which histogram? Determining your
E.I. is starting to look pretty good now, isn't it?
The understanding of this "histogram
disconnect" is fundamental to producing top notch work, yet how many
image creators understand the implications with regards to your color
correction options later on in Photoshop?
Andy Klement - in a post yesterday you mentioned a
disconnect between the JPEG preview in C1 or LeafCapture and the RAW file.
Can I get a little clarification? I would assume, perhaps incorrectly, that
you're using this software in a tethered shooting situation. If so, C1 is
using a TIF preview generated based on your parameters such as white
balance, exposure, etc. This should match your file as it is output and
opened in Photoshop. As this is getting WAY off topic, feel free to e-mail
me separately.
Darren Bernaerdt
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Geoff Shearer"
Wed Feb 7, 2007 8:12 pm (PST)
I want to take a moment to say that Lee's book is
excellent, and anyone interested in learning more about his techniques will
find in it a wealth of information. As a portrait photographer it is one of
the three or four best books I have read regarding photoshop technique.
Lee, thanks for your efforts. Please let us know when
your updated procedure is finished and how we can find it.
Geoff Shearer
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Andrew Rodney"
Wed Feb 7, 2007 8:12 pm (PST)
On 2/7/07 4:29 PM, "dbernaerdt" wrote:
I get the opportunity to hire photographers outside my
market roughly
a half dozen times a year, work with supplied images
daily, and
create original photography daily. What I see is either
a trend that
photographers are more sloppy than in the past and/or
perhaps more
more people are calling themselves a photographer
without a clear
understanding of the tools they are using.
I'd say both. Everyone is a photographer. When I used
to shoot professionally (I did a lot of annual reports and a fair bit of
adverting), uncle Joe would often get the job because he was a dentist and
had a Hasselblad and the company was trying to save some money (sure). That
was in the early 80's and I suspect this has gotten worse.
The composite histogram on the camera's display will
change depending
on whether sRGB or AdobeRGB is selected in the camera.
It also
changes if the tone curve is changed. It changes again
depending on
the white balance setting on the camera.
Yup. That's kind of a problem if you're shooting raw
only because those data points are kind of useless. You can begin to
extrapolate a difference between the two over time. Heck, we used to shoot
Polaroids like mad, then mentally adjust in our head what the chrome would
look like. AD's got good at this as well as they and the photographers
communicated what the image should look while looking over the 'roids'.
So how are we supposed to "expose to the
right" with precision?
First, as I mentioned, you need to know the actual ISO
of the chip. Then you have to learn how to use either a spot meter (and
know where to point it) or an incident meter etc and you may need to
introduce exposure compensation to get as close as you can to this ideal
expose to the right. But if you're off half a stop (which is kind of a lot,
we used clip test 1Î4 stop in the E6 lab), you're going to be OK. You
do want to avoid under exposure. Point is, the old "expose for the
shadow, develop for the highlights" mindset is different with digital
capture.
The understanding of this "histogram
disconnect" is fundamental to
producing top notch work, yet how many image creators
understand the
implications with regards to your color correction
options later on
in Photoshop?
A few less than those who can set the color settings in
Photoshop <g>.
It's an educational issue no question. The first
digital camera I shot was a very old, heavy Kodak DCS-1 and I suspect a lot
of photographers got onto the bandwagon a lot later. In fact, digital
capture really took off only a few years ago. Its a very young technology
and the tools are evolving now quite nicely. I think that's the point of
this long set of messages about ACR. You really shouldn't look at this with
Photoshop tinted glasses. Photoshop is a pixel polisher.
Andy Klement - in a post yesterday you mentioned a
disconnect between
the JPEG preview in C1 or LeafCapture and the RAW file.
Can I get a
little clarification? I would assume, perhaps
incorrectly, that you're using
this software in a tethered shooting situation. If
so, C1 is using a TIF preview generated based on your
parameters such
as white balance, exposure, etc. This should match your
file as it is
output and opened in Photoshop.
Well maybe it should.... Remember that the JPEG (or the
rendered TIFF) is simply one interpretation. Now as I said, camera
manufacturers are pretty good at rendering images. You don't hear customers
complaining much about the JPEG rendering. It would be useful if all (or
some) raw converters could produce a prefect match in the neutral settings
as the JPEG. The camera manufactures are better prepared to do this and
here's one of the rubs. A lot of the in-camera rendering is highly
proprietary! Canon doesn't want Nikon knowing how they do this and vise
versa. Wasn't that different in the film days either. Can a 3rd party raw
converter make the two match? Yes I think so and I think we'll see this in.
But its possible that just as many photographers will prefer a different
rendering. That's the beauty of raw. You're not stuck with a backed
rendering some computer thinks you want. Funny, we hear on this list how
any "auto" correction technique, auto sharpening or how profiles
can't possibly handle the complex job of color conversions yet many here
are in love with the idea of a set of chips in a camera producing the best
rendering without human intervention.
Andrew Rodney
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "zthreen lists"
Wed Feb 7, 2007 9:40 pm (PST)
On Feb 7, 2007, at 4:42 PM, Andrew Rodney wrote:
It would be useful if all (or some) raw converters
could
produce a prefect match in the neutral settings as the
JPEG
I believe Canon's own DPP does. It's designed to offer
the same controls as the camera, supports the same Picture Styles. So even
if you shoot RAW, you can still get the exact same result as if you'd shot
JPEGs by using DPP to process. I don't know what the situation is with
Nikon.
So you can even get the JPEG results you would have had
in the camera at a later date shooting RAW. As machines get faster, the
time to process batches drops, but shooting JPEGs in camera will always be
faster in really critical time-sensitive cases (or cases where file size
issues are a concern).
Matthew Rigdon
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "dbernaerdt"
Thu Feb 8, 2007 5:58 am (PST)
Matthew,
Same with Nikon Capture - it honors the camera's
settings. I haven't tried Capture NX (the latest version), however Capture
4 wasn't exactly a speed demon when it came to RAW conversions.
Darren Bernaerdt
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Hoffner, Randall N"
Thu Feb 8, 2007 8:59 am (PST)
A bit is indeed a quantization level, which may also be
considered a step on the light intensity ladder.
Randy Hoffner
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Hoffner, Randall N"
Mon Feb 12, 2007 4:12 pm (PST)
For the sake of accuracy, here is the difference
between a "bit" and a "quantization step":
The total number of quantization steps for a 12-bit
sample is indeed 4096 (2 to the 12th power). Each power of two (each
additional bit), doubles the previous number of quantization steps. So half
of the 12-bit data (representing a one-stop reduction of light intensity)
is not 2048 bits, but rather 2048 quantization steps, which is 2 to the
11th power or 11 bits. The bottom one-stop range, that range between the
fifth and sixth stops below maximum intensity, is represented by the range
between 128 quantization steps and 64 quantization steps (between 7 bits/2
to the 7th power and 6 bits/2 to the 6th power), a total of 64 quantization
steps. Any intensity below 6 stops is by definition out of range. So while
the brightest stop of light intensity is represented by 2048 quantization
steps, the least bright stop is represented by only 64 quantization steps.
Statistically, the larger the number of quantization steps available, the
closer any given sampled value will be to a step, and thereby, the less
quantization noise will be generated.
A bit is a binary digit, and each binary digit
represents a quantity greater than the digit to its right by a power of two
(in the decimal system, we well know that each decimal digit represents a
quantity greater than the digit to its right by a power of 10). So the
first bit (2 to the first power) represents 2 discrete levels (it's either
on or it's off). The second bit (2 to the second power) represents 4
discrete levels. And so on up to 12 bits or 4096 discrete levels.
This is true of digital photography, digital video,
digital audio, and any other situation where a waveform is sampled and
digitized.
Randy Hoffner
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "George Machen"
Sat Feb 17, 2007 3:41 pm (PST)
Wait a minute! That Camera Raw image ain't any old
grayscale image. While nominally a "grayscale" image, it's
actually one with a *color* image encoded therein: Each adjacent pixel is
the luminance value of a color channel after the incident light being run
through a color filter (whether in a Bayer pattern, Foveon, or whatever).
So a raw "grayscale" utterly *reeks* of color! (Never mind that
it hasn't yet had applied a gamma or been rendered a colorimetric scale
factor or gamut that a human could interpret as color by looking straight
at it; it's still really a color image in the context of this issue.)
Consequently, aside from neutral-colored subjects,
making an overall master curve move on that "grayscale" image in
Camera Raw is just as destructive as doing so on a rendered regular color
image in Photoshop.
With the possible exception that, while Bruce Fraser's
Camera Raw book does contain one sentence stating that Camera Raw uses an
algorithm to preserve color shifts during such master adjustments (like a
Photoshop Color layer mode or Fade command, I guess), that still leaves the
obliteration of tonal detail & contrast from an overall move (i.e.,
there isn't an algorithm providing a constraint analogous to a Photoshop
Luminosity layer mode or Fade command ... and even if it did, what furthter
adjustment then could be possible?).
I like Dan's explanation of the issue involving the
example of three images of cats: a white cat, a gray cat and a black cat.
Increasing contrast of the white cat image needs a steepening of the
highlight-to-quartertone area in Curves. The gray cat requires an
"S" curve widely about the midtone. The black cat necessitates a
steepening of the threequartertone-to-shadow.
Each of the three moves is exclusive. If one is unlucky
enough to have one image containing all three cats, no matter which of the
three moves one does, the other two cats get hosed.
The upshot for a color image is that (and again, other
than for neutrally-colored subjects, where a master curve move in principle
doesn't present the problem), almost every color image's individual color
channels contain a white cat, a gray cat or a black cat. Therefore, making
an overall Curves move is practically guaranteed to kill parts of an image
unneccessarily, which could be avoided with individual channel moves.
(This also is why Camera Raw's auto-contrast
"S" curve always is at the expense of highlights & shadows.)
Camera Raw's Curves needs individual color channel
adjustments separated out on those "grayscale" image's adjacent
*color* pixels.
(Hold it, by the time one gets to Camera Raw's Curves,
aren't we already demosaiced into the RGB native camera space or even into
the linear gamma ProPhoto RGB intermediate space, anyway? But it's a moot
point.)
Until then, for color correction purposes, we're a lot
better off taking it into Photoshop to do our individual channel Curves
moves. Who cares if it turns our histogram into a comb, if the final image
looks better?
- George Machen
___________________________________________________________________________
Re: Camera Raw Settings
Posted by: "Mark Segal"
Sun Feb 18, 2007 7:22 am (PST)
My understanding of this matter is that the version of
the image received into ACR is all the greyscale pixel data in the image
file, tagged as it is with red, green or blue according to the Bayer
matrix. ACR de-mosaics these pixels to produce the colour one sees. So for
example if you set your camera WB to bluish values you'll get bluish
looking ACR images, etc. But it doesn't matter, because you can shift the
WB to where you want it in ACR - mix to taste. Photoshop CS2 introduced the
tone curve into ACR. I have been using it ever since on a broad variety of
images and I have not noticed it hosing anything. May-be that is because I
use it carefully, avoiding clipping and watching for any impacts on
saturation and detail. Whether this tone curve actually CAN IN THEORY
produce the negative effects you mention I don't know, because I don't know
the mathematical algorithms impacting ACR data from the application of this
curve. Perhaps you do and perhaps you have experimented with it enough to
produce the difficulties that Dan mentions in Chapters 2 and 3 of PP5E. It
is factually correct that ACR3 does not have separate curves for each
primary and it looks as if ACR4 will not either. But ACR3 is now history,
as ACR4 has a large number of new tools and controls that may allow one to
achieve similar results without actual individual channel moves. No-one I
know has done the kind of testing with the new product that would address
that question.
Mark Segal