Photoshop Layer Curiosity

[marcsitkin]

I have just had an unusual problem in Photoshop. I'm working with an artist to prepare a series of canvas prints with a uniform sepia tone. I started with some supplied CMYK files that were all over the place colorwise. My test procedure, which seemed to work fine was to:

• Open each file
• Convert to RGB (adobe)
• Apply 100% desaturation
• Copy and paste them into a new RGB file (adobe) to create a 4 up sheet suitable for printing the width of my printer

We added a color mode layer with a sepia tint, adjusted color and used a custom blend to control the ratio of toning from shadows to highlights
Also added a hue/saturation layer to increase overall saturation and decrease yellow saturation.

After getting to a successful color, it was time to re-create the effect on the original files.

I opened the first file, and went through the same steps as on the testing.
I dragged and dropped the tint and saturation layers, stacking them in the same order, onto the modified original.

Suprise, suprise, the color was off by about a3 and b6 in LAB measurements

The fix was to rework the tint layer to correct the color.

The question is why did that need to be done?

[JeffKohn]

Were the original files you dragged/dropped onto in a different color space? When dragging pixel data it will allow you to do the appropriate color conversions depending on your color management settings; but my guess is that adjustment layers are not colorspace-aware, so for instance the affect of a saturation change in AdobeRGB would be different from applying the same change (as a numerical value) in ProPhoto or sRGB.

[marcsitkin]

Were the original files you dragged/dropped onto in a different color space? When dragging pixel data it will allow you to do the appropriate color conversions depending on your color management settings; but my guess is that adjustment layers are not colorspace-aware, so for instance the affect of a saturation change in AdobeRGB would be different from applying the same change (as a numerical value) in ProPhoto or sRGB.

Both source and target files were Adobe RGB, which is what I find puzzling. I went in and created a new color layer and hand input the values of the test file, and still had errors. I'm beginning to think that the test file's color layer was somehow corrupt.

After getting back to proper color on the first full size image, dragging and dropping the color layer worked perfectly between full size images.