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I just received my copy of PS CS3 and began to play with the curves to see what was new and improved. I noticed something, and I hope that I am wrong.

You can no longer change the axis orientation in RGB to be the way Dan suggests (so it is the same as CMYK, with highlights to the left) Unless you also tell it to display input and output values as a percent of pigment (from 0 to 99 %) instead of as a value of light (from 0 to 255).

Now, I am a relative novice at color correction, so maybe this is more of a problem for a person like me than you pros. I have a hard enough time doing color correction by the numbers. It's hard to get the points on my curve just where I need them to be, and I'd really like the display to show me numbers from 0 to 255 when I'm working in RGB. But now I can't have that, and also keep my curves with the axes oriented as Dan suggests.

Have I missed something? The documentation for CS3 is as cryptic and minimalist as ever, and with the upgrade version you don't even get a printed manual anymore. So if I missed something, please let me know.

By the way, the documentation also says that Ctrl-clicking (on Windows, Command-clicking on Mac) within the image to put a point on the curve only works in RGB mode. They are wrong, at least on my Windows machine; it also works in CMYK mode, just as before.

I will report any other "improvements" in the new version that can ruin the day of a color corrector, and encourage others to do the

same.

Ronald Greenberg

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You also can't enlarge the curve box which is critical when writing LAB curves although the curve dialogue box is now slightly large than CS2.

Wai-hong Chung from Hong Kong

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On 4/27/07 9:37 PM, "tbexposure" wrote:

Did you play with the ©¯Show Amount of©˜ Radio buttons? I think you want Pigment Ink radio button.

IT is the large size now (the smaller size option is gone). In the CS3 size, it©ˆs identical to the CS2 curves (minus new options) so its not slightly larger...

Andrew Rodney

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On Apr 27, 2007, at 8:37 PM, tbexposure wrote:

I don't know that it ruins the day. If you hover over, you see that Light shows additive in the tool tip, while Pigment/Ink shows subtractive. From a scientific perspective, charts and graphs generally always put the 0,0 point in the bottom left corner. It also bears mentioning that if you're working in 16-bit, a color scale from 0-255 has to be "converted" in your head to the actual value. There's an adjustment, but I don't think it's any harder than having to learn how to swap RGB, CMYK, and LAB values in your head. At least you can find all the display options now (look , a button to bring up 10% increments, how novel!).

It's nice to have a histogram in there now, so it should help when you first learn curve writing. You can now grab the white and black points from the display at the bottom and pull the ends of the curve that way. I find sometimes I end up pulling an endpoint down as well as left or right, so this is a nice feature (sometimes my mouse gets a little jiggly). I don't find the size to be an issue. It's a little bigger than the old Curves, a little smaller than the old Curves blown up, so maybe it's about right. :)

Matthew Rigdon

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Ronald, with a firm grasp on the most basic principles of contrast and colour adjustment, it should not matter to you whether the values are expressed as percentages or as absolute numbers. The scale of 0 to 255 is only relevant for 8 bit colour depth. With many practitioners now taking advantage of higher speed computers and cheap storage, we are editing our images in 16 bit mode, where the number of discrete levels changes to over 32,000 in Photoshop. Hence the 0 to 255 scale does not reflect this reality. Keeping the scale in percentage terms is neutral with respect to one's choice of 8 or 16 bit Image Mode. So whether you call middle grey RGB 128/128/128 or 50%/50%/50%, you will still get middle grey. And if you don't have a library of colour recipes stated in the 0-255 scale, you won't be missing much. The change in habit should not be difficult. While I work mainly in RGB I do my corrections both visually and by the numbers using LAB values as guidance because I can

relate my shifts of the Green and Blue Curves to the "a" and "b" values of those two LAB curves quite intuitively, and these values are on a scale of 1 to 100. (I can work this way between visual and "by the numbers" correction because I have a properly calibratred and profiled monitor using a good colorimeter.) As well, being able to read the L values on a scale of 1 to 100 also helps me to better predict (along with soft-proofing, which is reliable in a color-managed workflow) how the darkest and lightest tones will emerge from the printer, because I know from grey-scale tests (where the test target images use scales graded from 0 to 100) what my particular combination of paper and ink performs like.

As for documentation, perhaps your's has not arrived yet, or perhaps it makes a difference whether you order the box or a download up-grade, but I ordered the box. The program box and the manual come in two separate deliveries, the manual after the program box. The manual has the look, weight and feel of a white brick, coming in at 823 pages, with lots of very clear, practical guidance on how to use Photoshop. It is not a theoretical treatise of the whys and wherefores of Photoshop, but rather a results-directed orientation about how to use the program. I think it is by far the best and most comprehensive Photoshop manual Adobe has ever issued.

Mark Segal

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Click on 'Curve Display Options'

Graham Bird

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Ronald Greenberg wrote:

Yes, this was/is no surprise to me Ronald. Do you have an earlier version that you can fire up and compare?

No, this is legacy behaviour, Photoshop has always been this way.

The 'feature request' that you 'propose', is perhaps worthy though!

This is in reference to the composite 'master' channel and not individual channels. In CMYK, one can't add a control point by clicking on the image when in the master channel, but it does work when the curve display is editing a single channel.

When doing 4C work, the ctrl/shift/alt or cmd/shift/opt click on the image when in the master CMYK channel is very useful.

Please do so Ronald, I personally prefer the legacy versions layout for the smaller footprint, and that was not ideal. The only addition in CS3, which I find *really* useful, is the diagonal neutral reference ‘baseline’. The intersection lines are OK, I can turn off the histogram but may leave it on and never really take note of it in relation to my edits and the channel overlays are usually off.

Stephen Marsh.

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Dear List, I would like to request that the thread on the CS3 curve problem end, or more importantly - that *only* on topic replies to the question raised by Ronald be posted from this point forward.

Ronald *is aware* that it is possible to swap the axis of the curve display - that was not his question, despite the many answers informing him of this. With more careful reading, one will see that the real problem is:

Which I answered in this in post:

http: //tech.groups.yahoo.com/group/colortheory/message/17440

Unless anybody has a way for the curve display to show RGB 255 scale values when in the CMYK curve display axis (reading as % not 255 values), then there is no point with more posts on the curve axis radio buttons.

Ronald, I would suggest that you place averaged fixed colour samplers on the image and evaluate the results in RGB there in the info palette, rather than in the curve dialog box (it is usually more important to know what the curve is doing to the image, rather than what the curve edit point is doing in isolation, divorced from the image).

Regards,

Stephen Marsh.