Photoshop Help is actually helpful this time for Darken mode:
Looks at the color information in each channel and selects the base or blend color–whichever is darker–as the result color. Pixels lighter than the blend color are replaced, and pixels darker than the blend color do not change.
And here are two examples to help illustrate this:
Here are two images that I’m going to blend together. I purposefully made them two different colors, and also made sure that the light/dark values were different as well:
When I layer the two images on top of each other and set the top layer to the Darken mode, you’ll notice that the “darker” values show from each layer.
But the effect is even cooler when you start creating a montage with different photos or illustrations that have a lot of colors. Let’s take these two flower photos:
Once again, layering the images and setting the top layer to the Darken mode creates an interesting effect:
Because the cherry blossom picture has an area that is very light (the blossom), surrounded by a fairly dark background (the tree trunk), the yellow rose part shows through in a pretty defined area. I like it!
Just to demonstrate that Photoshop is really taking the darker value for each pixel, I’ll switch up the layers so that the rose layer is on top, set to Darken Mode. The end result looks exactly the same!
Now for the deeper practical application, which I originally learned at www.digitalretouch.org…
Because Darken Mode takes the darker value of two layers, it is ideal for retouching scanned photos that have light specks (old photos tend to get dust embedded into them, which then get scanned in with the rest of the photo). How? Keep reading!
1. Let’s take an older photo of yours truly, taken when I was almost one year old. Looking closely (which I’ve conveniently provided in a close-up cutout), you can see that the scan of the photo has light-colored speckles:
2. The first step to a quick fix is to duplicate the layer. Then, I’ll add a layer mask to preserve the finer details of the image — i.e, the facial features and the lighter parts of the images that don’t need retouching.
3. Then, set the mode to Darken. No change yet — that’s fine.
4. The second crucial step is to select the move tool, then use the arrow keys to gently move the “Darkened” layer down 2-3 pixels. This offsets the layers enough so that those darker pixels are selected over the lighter dust-speckled pixels, as you can see in the “Before” and “After” cutouts.
Cool, eh? Obviously there are still some other problems with the photo that would need to be retouched, but really — with a super-fast four-step process, that’s not too shabby.
Lighten Mode works much as you would expect after being exposed to Darken Mode: Lighten Mode picks out the lighter pixels. So, the same type of application works; if you have photos that have dark-colored specks, then do the same tiny shift in pixels and use Lighten Mode to hide the specks.
Any other great ideas or examples of using Lighten or Darken modes?