How would you produce grey-filled Overlay layer from two layers that differ in brightness?

Question

Here is what I want to achieve. Let's say I have base layer which is some photo. I'll make a copy of it and apply Shadows/Highlights filter on it.

How would you produce 18%-grey-filled layer from these two layers so that application of this new layer to base layer in Overlay mode would produce close effect as Shadows/Highlights filter ?

I know dodge/burning with overlay layer give saturation shifts but let's say it's not a problem in this case.

Answer 1

Well Shadow/Highlights will darken highlights and lighten shadows.

In Overlay mode, lighter grays will lighten and darker grays will darken.

So if you want to darken a highlight, you need a darker gray. To lighten the shadows you need a lighter grey.

In other words, you need an inverse of the original image, to some degree.

What I would do is start with a blank 50% gray layer. Then I would select the gray layer, and go to Image > Apply Image

• Source Layer: select the background layer (or wherever your main image is)
• Channel: select RGB and check the Invert box
• Blending: start with Overlay

Then adjust opacity to get the effect you want. It will be somewhat like Shadows/Highlights.