Pulling details out of shadow in Photoshop with blending modes
Let me start with this: I AM NOT, NOR CLAIM TO BE, A PHOTO EDITING MAESTRO. There are many folk out there who are veritable wizards with Photoshop and the plethora of image editing programs out there. I am simply a photographer who likes to make the most of the tools at my disposal.
To me, going from seeing an image in front of me (and more-so in my mind) to having the finished product in my hands or on my monitor is a process where each step complements the next. Many photographers say “get it right in camera” rather than relying on Photoshop to fix poorly executed images. I agree with them completely, however, there are situations where the limitations of the tools we’re using make it necessary to think about the next step (ie how you’re gonna process the image) before you press the shutter release, as exposure settings will make a big difference to how the image can be processed later.
For digital images, it’s impossible to pull detail out of areas that were so bright when the exposure was taken that they’ve blown out. On the other hand, there is some hope of pulling detail out of areas that look as though they are pure black. Focusing on what’s important in the image is the first step in working out if you’re willing to lose detail in the bright areas to save detail in the shadow, or vice versa.
When I was in Australia on holiday with my wife last Christmas, I ran into an instance of where I had to make careful considerations when exposing in-camera, and where a little understanding of some simple Photoshop techniques saved the image.
Here’s a before and after of the image in question. What made the situation messy was that to the right was an extremely bright background, to the left was an area in shadows that included the main subject – my wife. Now, there would be a range of ways to deal with a situation where levels of light are quite different (referred to as a high dynamic range). One way quite in vogue over the last 5-10 years is to take multiple images with different exposures and to then combine them to bring out detail in both the very bright and very dark parts of the image. This is called HDR merging. While there are some amazing images that result from HDR processing, to me, it can look a little artificial and can be particularly ugly and impractical for portrait images.
The next solution would be to set up a flash or two to brighten up the shadows a little while allowing the bright areas to not be overexposed. That wasn’t really practical in this case either, as we were simply waiting to meet a friend and pulling out lights and stands would be ridiculous. This was just a snapshot taken to kill a little time and remember our trip.
The third solution is the one I chose:
Figure out what’s important in the image, and make sure your camera records enough detail to save those parts afterward in Photoshop (or Lightroom or whatever you like to use). For me, obviously my wife was the important part, so I wanted to make sure she was well enough exposed to bring her out later in PS. The critical point here was her hair, as it is quite dark, and dark hair in shadows can easily fall into pure blackness that you’ll never be able to save in post. On the other hand, I didn’t want the background to become so blown out that there was no detail there. So I made the decision to lower the exposure to save as much detail in the background as I could while still preserving detail in her hair. I knew that that would give me the most chance of saving the image later in Photoshop.
Now, that’s only step one – capturing the image. That gave me this:
You can see the hair is quite dark, but not purely black, and only the teeny tiniest part of the background is blown out (pure white). It’s pretty obvious though, that I really had to brighten the left half of the photo so that my wife wasn’t sitting in shadow.
Two popular ways of adding brightness in Photoshop are to use Curves, Levels, Shadows and Highlights or Brightness. I’m here to tell you that there’s another way to do it that in many cases produces much better results than any of the above (I do use all of the above in various situations, but don’t limit yourself to them alone).
Here’s a version of the image that was brightened using curves and brightness.
It’s not a bad start, but certainly nothing to be all that happy about. The hair is lacklustre and still quite dark, and my girl’s skin is a little unnatural looking.
So what’s this amazing alternative method I used to produce a more natural-looking image? Actually it’s quite simple, but often neglected as a lightening tool…
It’s the Screen blending mode. A blending mode is basically a different way for a layer to interact with the layers below it in Photoshop. What I did was to duplicate the image as a new layer (Ctrl+j will do the trick on PC), and to change the blending mode to screen. Honestly, I don’t know how it all works, but I do know that the screen blending mode is a great way to bring some detail out of shadow, and also to brighten parts of the image (brighter eyes and teeth on a portrait, for example).
Here’s the image brightened that way:
To me, it’s a more natural result, and best of all, there’s a lot more detail in the hair that other methods didn’t bring out.
While we’re talking about blending modes, try duplicating layers and seeing how other blending modes affect the image. I am quite a fan of a few other blending modes, my favourite being Multiply, which brings a great intensity to an image and works great for increasing contrast and saturation in an image when dialed down to a more subtle opacity (around 10-20%). You’ll find that duplicating the image to a new layer and using a different blending mode will solve many issues more effectively than some of the more traditional Photoshop tools.
Good luck, and have some fun playing around with blending modes, they’re a really useful thing!