Photoshop: Gradient Map does not allow to select colors from an image

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CS5, Using Legacy Channel Shortcuts Option ON.

Scenario:
RGB image, launching Gradient Map, selecting Gradient Editor, selecting Color Stop, selecting Stop Color - Select Stop Color Dialog Box is displayed. Pointing Cursor over the Image Area to sample colors from the Image.

Result:
The Eyedropper is reading values from the Layer Mask attached to the Gradient Map Adjustment Layer instead of reading values from the Image.

Observation:
Photoshop attaches a Layer Mask to a Gradient Map Adjustment Layer and by a default leaves the Layer Mask Selected. Photoshop then reads values from Layer Mask rather then values from actual Image.

Runaround:
Launch Gradient Map Adjustment Layer.
Click the Layer Thumbnail to Deselect the Layer Mask then proceed to edit the Gradient
or
Delete the Layer Mask then continue to edit the Gradient.

Was this intended? And if the answer is yes - what are the benefits of Selecting grayscale values from Layer Mask to edit the Gradient?
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roman weiser

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Posted 8 years ago

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Chris Cox

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You have the layer mask targeted, so the eyedropper will read from the layer mask as intended.
Yes, you should make sure you target the layer color if you intend to read from the layer.

And it works that way with all adjustments. (answering why would require a long discussion)
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roman weiser

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Chris, thanks for the prompt response. I have a couple of points and questions:

1. You said: "You have the layer mask targeted, so the eyedropper will read from the layer mask as intended."

I know, I acknowledged that in my Observation section, but - what is the reason for grayscale values from Layer Mask to be considered in adjusting a color image? Doesn't it seem a little un-intuitive? IMHO it does not make sense and I believe this was NOT intended.

____

2. Gradient Map is very unique in a group of Adjustment Layers. There is no other Adjustment Layer that I know of, that interacts with adjusted image by sampling it's values for adjustment or further color editing. Am I wrong here?

____

You said: "And it works that way with all adjustments."

3. That's incorrect Chris. No other Adjustment Layer's functionality depends on what thumbnail is selected. Layer thumbnail or Layer Mask thumbnail, they all (except for Gradient Map of course) function the same either way.

Chris, I am willing to spare no time when it comes to help you to improve this great program and unlike you - I'm not getting paid for it. ;)

Your point does not stand, so please go ahead and start this 'long discussion', educate me, help me understand. Who knows, maybe we together find another little thing to help Photoshop remain the best image editing program on the market. What do you say?
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Chris Cox

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1) it is intended as long as you have the layer mask targeted. And for gradient map, most people are not sampling colors from the image (because the image will be changed by the map).

2) Again, I don't see much point in sampling from the image for gradient map. It's just that many of the adjustments CAN sample from the image, so the eyedropper functionality is there for all adjustors. And if you open the gradient editor and color picker, you should be able to sample from the image (even if it doesn't make much sense for that particular adjustor).

3) All the adjustments should be behaving the same in that regard. Try the Photo Filter (which can also sample color), or double click the color eyedroppers in levels, check the color sampled by the eyedropper in selective color, threshold, posterize, etc. Yes, it may not be what you expect, but it is fairly consistent for adjustments that don't have a tool for specifically measuring color from the image. And gradient map isn't designed to directly measure color from the image.

Yes, it would probably be better if the color picker eyedroppers used from an adjustment layer switched to the composite color channels by default instead of using the targeted mask. But what's there is not exactly a bug, just something that could be improved.
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Jan Vork

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E.g. to match two monochrome-style old photos (not greyscale) for head replacement.
I make the new head's levels from black to white, then with a Gradient Map, I match the colors. But alas, picking from the underlying original photo is a hassle.
(Edited)
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Jan Vork

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A switch in the Gradient Map editor will do: Sample All Layers.
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A K

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I wish there were a way to do this.

1. One solution would be to alt-click (or something like that) to make the eyedropper sample all layers.
2. Just because you don't find a need for this in your work, doesn't mean others won't. I've often liked the colors and tones of an image and wanted to model a gradient on those very tones, then to save the gradient. Currently this is a painstaking process because I can't see the gradient update live. This is only one example of when I would want this feature.
3. See point 1

Maybe if there's enough call for it, this will happen.

One work-around is to make a gradient overlay in the layer style. Set the opacity to 0% then start sampling. Save the gradient and then use it in the gradient map.
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Jim Ainsley

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This issue bugged and confused me for years and years!

The solution is simply to click off the mask layer and on to the adjustment itself! :)
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eartho, Champion

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Or they could change the behavior so that when adding an adjustment layer, the adj is targeted instead of the mask. Even better would be that sampling always ignores the mask when an adj layer is selected.
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Jim Ainsley

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Good idea. I can't think of any reason why anyone would want to sample a greyscale adjustment layer. Common sense says you always want to sample the image itself, obviously.
(Edited)