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First of all, my thanks to Stephen Marsh for generously furnishing me with enough information about the practical applications of the Blend-If sliders that I had no choice but to take the time to figure out how to use them. Since then a couple of Forum contributors, who have also helped me in the past, have expressed their frustration with the perceived complexity of this tool. So here's a simple explanation that hopefully will clear this up for all those who are still wondering how the Blend-If sliders work. Like most things in Photoshop that look easy once you understand them, this explanation was literally months in the making.

The Blend-If sliders in the Layer Styles dialog box are labeled This Layer and Underlying Layer. Both have a black (shadow) pointer on the left and a white (highlight) pointer on the right. Both sliders represent the full range of tones possible in an 8-bit image. For an RGB image, each slider represents a range of 0 (shadow) to 255 (highlight). As long as neither slider's pointers are moved, neither slider affects the active layer's appearance.

Now, if you move one of the sliders for a given layer, it specifies the range of possible tones on that layer that will affect the appearance of the active layer (huh?).

But be patient. Moving one or both pointers doesn't compress any tones. In the case of the top slider, any tones outside the two pointers drop out of the image just as if the pixels representing those tones had been selected with the pen tool and subsequently deleted. Of course this means that the underlying image will now be visible wherever the top layer pixels (repesenting those selected tones) have become invisible. The confusing factor is that the Underlying Layer's sliders behave differently. Instead of disappearing when you move the pointers, any pixels representing tones that lie outside the pointers on the underlying layer are effectively duplicated and blended into the topmost layer.

If this is still confusing, consider this example. You move the two This Layer pointers so that the range between them is narrowed to values from 45 to 200. If you turn off the visibility of the bottom layer, you will find that all of the top layer's pixels representing tones from 0 to 44 and from 201 to 255 have become invisible, thus permitting anything on the underlying layer to show through wherever the overlying layer's pixels have effectively dropped out. No pixels on the top layer will be blended with the pixels on the bottom layer. They just disappear. Now, forget about the This Layer slider. Let's look at the Underlying Layer. If you move the Underlying Layer's highlight pointer to the left to a value of 210, you will find that the pixels representing tones of 211 to 255 in the bottom layer do not drop out. Instead they blend into the image on the overlying layer.

If you hold down the Alt (Option) key while clicking on the innermost half of a pointer, the pointer will split into two parts, permitting you to move the innermost half without disturbing the other half. This gives you a feathering effect analogous to the effect you get by blurring a selection.

There are other features in the dialog box, but one thing at a time. Just knowing the above will give you what you will need for almost any job where the Blend-If sliders can be used. Forget about proper settings and recommended uses. Now that you know how the sliders work, keep experimenting untill you find out how you can best use them on your own images.

Howard Smith

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Thank you for your explanation. I wonder if there is a way for making a layer from a Blend if layer style. I know that in the layer styles menu there isn't such option, if anybody knows some trick...

TIA

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Claudio Corvino

Florence, Italy

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To create a new layer from a layer style, create your style (e.g., a drop shadow) and then choose Layer/Layer Style/Create Layer. You may get a warning from Photoshop that you can't do this with all styles, but go ahead and try it with the one you are using. In the case of the drop shadow, your drop shadow will appear on a layer of its own. Unfortunately, one of the things that will not work with this method is the Blend-If sliders. The best you can do in such a case is to make duplicate layers for use with the Blend-If sliders, put these layers into a set and then apply the sliders to the layers in the set. This gives you the option of blending the effects in your Blend-If set with the original image.

You can also copy a Blend-If layer style and paste it into a new image. To do this choose Layer/Layer Style/Copy Layer Style, open the new image and choose Layer/Layer Style/Paste Layer Style.

Hope this answers your question.

Howard Smith

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On Jul 28, 2005, at 5:12 AM, claudio corvino wrote:

Are you referring to setting the layer style on the top layer, doing a merge visible layers to a new layer and then turning off the layer style that you previously set?

Jim

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Thank you for this explanation. Reading Real World Photoshop CS with Fraser's use of Blend-If sliders for tuning initial capture sharpening had given me a start in understanding this blending, but your details have helped immensely.

Thank you

Craig Sutherland

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Three months later, the subject reopens:

Hi! I've also been trying to find a more in depth explanation on the Blending Sliders. I wish I could find another source which would go into more detail than Dan does. He presuposes that the reader is already well versed in this and other techniques in the book. I realize and must admit this is one of a few "lagoons" in my understanding of PS.

Any suggestions will be appreciated!

Wishing you all the best!

Paco Márquez

661 McKinley St.

MIramar

San Juan, PR 00907

787-721-8554

787-587-7384 Cel.

http://www.pacomarquez.com

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dan does a great job of demonstrating the blend-if functions in canyons (plenty of real-world examples).. I also struggle with the blend-if concepts.. but if you simply pay attention to the example's process & details..including utilizing the individual channel options you will surely catch on.. just as we all needed to work on a few hundred (or more) images to acquire the other associated skills.. you need to roll up your sleeves and actually work on blend-if.. something that I have yet to do...

all the best, jim bean

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Hi Jim,

Thanks for the reply. What you suggest is exactly what I am doing and I think I'm catching on. Just got to roll the sleeves further upl. :-)

Wishing you all the best!

Paco Márquez

661 McKinley St.

MIramar

San Juan, PR 00907

787-721-8554

787-587-7384 Cel.

http://www.pacomarquez.com

___________________________________________________________________________

Paco,

Without knowing exactly what you need to know about the Blend-If sliders, I'm not sure if the following will help. In case you missed it, let me know what part of it is bothering you. If you consider the following and use them a few times for a variety of tasks, it should all become clear. As far as following Dan's examples, sometimes people interpret instructions in different ways. I've found that sometimes it helps to explain a thing several different ways. One of them will make sense while the others may not. Anyway, here you are in case you don't have this information.

The Blend-If sliders in the Layer Styles dialog box are labeled This Layer and Underlying Layer. Both have a black (shadow) pointer on the left and a white (highlight) pointer on the right. Both sliders represent the full range of tones possible in an 8-bit image. For an RGB image, each slider represents a range of 0 (shadow) to 255 (highlight). As long as neither slider's pointers are moved, neither slider affects the active layer's appearance.

Now, if you move one of the sliders for a given layer, it specifies the range of possible tones on that layer that will affect the appearance of the active layer (huh?). But be patient. Moving one or both pointers doesn't compress any tones. In the case of the top slider, any tones outside the two pointers drop out of the image just as if the pixels representing those tones had been selected with the pen tool and subsequently deleted. Of course this means that the underlying image will now be visible wherever the top layer pixels (repesenting those selected tones) have become invisible. The confusing factor is that the Underlying Layer's sliders behave differently. Instead of disappearing when you move the pointers, any pixels representing tones that lie outside the pointers on the underlying layer are effectively duplicated and blended into the topmost layer.

If this is still confusing, consider this example. You move the two This Layer pointers so that the range between them is narrowed to values from 45 to 200. If you turn off the visibility of the bottom layer, you will find that all of the top layer's pixels representing tones from 0 to 44 and from 201 to 255 have become invisible, thus permitting anything on the underlying layer to show through wherever the overlying layer's pixels have effectively dropped out. No pixels on the top layer will be blended with the pixels on the bottom layer. They just disappear. Now, forget about the This Layer slider. Let's look at the Underlying Layer. If you move the Underlying Layer's highlight pointer to the left to a value of 210, you will find that the pixels representing tones of 211 to 255 in the bottom layer do not drop out. Instead they blend into the image on the overlying layer.

If you hold down the Alt (Option) key while clicking on the innermost half of a pointer, the pointer will split into two parts, permitting you to move the innermost half without disturbing the other half. This gives you a feathering effect analogous to the effect you get by blurring a selection.

There are other features in the dialog box, but one thing at a time. Just knowing the above will give you what you will need for almost any job where the Blend-If sliders can be used. Forget about proper settings and recommended uses. Now that you know how the sliders work, keep experimenting untill you find out how you can best use them on your own images.

Howard Smith

___________________________________________________________________________

Howard,

Thank you very much for the explanation, it has helped me enormously! I truly appreciate the time you have taken to explain this.

Wishing you all the best!

Paco Márquez

661 McKinley St.

MIramar

San Juan, PR 00907

787-721-8554

787-587-7384 Cel.

http://www.pacomarquez.com

___________________________________________________________________________

Paco,

Something that helps you to see what's happening is to put a grayscale tones over top of a color image. A 20 step gray scale is good enough. Watch the individual tones as you move the blend-if sliders.

Lee

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Didn't I read recently or see someone state that a channel blending how-to book is being developed by some user somewhere? I thought I saw it mentioned here or on the Photoshop lists I belong?

I'd love to see this aspect demonstrated clearly because it's the biggest hurdle I have always faced when first reading about channel blending in Dan's writings, the WHY?

It's one thing to read it and say, ah, yes. It's entirely different for a slow learner like myself to sit in front of a project that is on deadline and say: Now which channel blends into what? Oh, yes, the CMYK Magenta, into the RGB Blu and at 50% OVERLAY. Holy, Bat S__t, that's alot to forsee.

Then there is the aspect with all this knowledge will it pay off ($). Alot of clients I see could care less if the results are sparkling clear well color balanced. The digital world has dumbed down people's expectations from a graphics professional. But maybe I'm wrong.

John Robinson

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Thanks Lee I was trying to figure out how to do this!

Paco Márquez

661 McKinley St.

MIramar

San Juan, PR 00907

787-721-8554

787-587-7384 Cel.

http://www.pacomarquez.com

___________________________________________________________________________

There was a book published in 1998, "Photoshop Channel Chops," by David Biedny, Bert Monroy and Nathan Moody (New Riders Publishing). It was meant to be used with Photoshop 4, and it has not been updated since then, I think.

All the same, it details procedures having to do with channels, alpha channels, layers, calculations, compositing and paths that are possibly still valid in today's Photoshop CS2. Of course, it would be great if someone updated the techniques described in the book with any new twists introduced in Photoshop after 1998, of which there are probably many.

Unfortunately, though the book is available as a used item on Amazon and Alibris and Abebooks, it's shockingly expensive: the lowest price among the ones available is $158.44 (gazoots!), and it goes all the way up to $495 (are you still breathing?)! I just read in PhotoshopNews.com that this book has become "the most valued collectible book in the world of technical trade publishing." No kidding...

Incidentally, Biedny is curating a Podcast series at this URL: <http://attentionphotoshoppers.libsyn.com>

He started it this last August, and in it he covers sundry aspects of high-end imaging. Please check it out: you may end up agreeing or disagreeing with him, but the man has lots of useful knowledge. (Unfortunately, it's just audio, no video.)

At a much lower price, there is another book, by Scott Kelby, titled "The Photoshop CS2 Channels Book," due to come out on December 27 from Peachpit Press. I know absolutely nothing about it, other than the advertising copy in the entry for it on Amazon.com. My sense is that it's written for beginners, not for expert users, but we'll see

Good luck.

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Marco Ugolini

Mill Valley, CA

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Paco, now that you have a basic grasp of the sliders, finding ways to use them will help you to see when they are useful and when they are not. The basic use of the sliders is in luminosity mode, which can be confusing enough. By altering the blending in separate channels and not just the composite, things get much deeper (which is what Dan often does in LAB mode, which makes the concept even harder to grasp at times as LAB is so different to other modes).

*Tonal edits: One can alt/option split the slider/s to reduce the intensity of tonal edits in one extreme tonal range while keeping full intensity in the other extreme (be careful, it is easy to posterize or plug tones if not being careful, I usually split the slider to the opposite extreme tonal point).

*Adding noise to a duped image layer: One can use the blend if sliders to exclude the noise from the extreme highlights or shadows, you may not wish 'scum dots' in pure white areas or pure black areas while the noise is wanted in tonal ranges which will be screened.

*Sharpening: It is often beneficial to use the USM on a duped layer, then to dupe the layer a second time. The first layer is set to darken blend mode at 100% opacity, while the other layer is set to lighten blend mode at say 50% opacity. This is a great method to tone down the light half of the sharpen halo, but it uses two layers which may not be ideal when speed is needed (also one does not evaluate the USM while in lighten mode, so it is not very interactive).

An alternative is to only use one duped layer for USM (luminosity blended) and to use the blend if to reduce the intensity of the light half of the USM halo. One simply opt/alt splits the highlight slider and drags it to the midpoint or extreme shadow point.

But which layer? The upper 'this layer' or the lower, 'underlying layer'? Compare for yourself. Should they both not be the same as each other using the same USM and slider settings? Compare for yourself.

Most people recommend splitting the upper layer. I don't, I recommend the lower layer in most cases (depends on image/slider settings).

The lighten/darken method and the blend if method of reducing the light halo of the USM layer are similar, but subtly different, mostly so in the hightlights.

Splitting the sliders has a very non linear affect on the ramping/gradation of the tone (Gassian?). Some other graphics apps offer blending sliders, but they are crippled - they have no way to split the sliders (which makes them nearly next to useless without then adding layer masks).

Stephen Marsh.

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Hi Stephen,

Just wanted to send a small note thanking you for taking the time to explain the Blending Sliders. Thanks to the responses I have received I am making quite a bit of progress here.

Wishing you all the best!

Paco Márquez

661 McKinley St.

MIramar

San Juan, PR 00907

787-721-8554

787-587-7384 Cel.

http://www.pacomarquez.com

___________________________________________________________________________

Scott Kelby has one scheduled to come out from Peachpit I think in December.

Lori Sabo