Fixing underexposed images in Photoshop
Even though we all try and get the exposure perfect in camera, from time to time things happen and exposure is off. It might be one shot out of a bunch that has the perfect expression but was under or over exposed and you have to fix it. Even though it will never look as great as if you had the perfect exposure and lighting, you can still salvage a bad exposure. Here are some ways to fix a underexposed image in photoshop.
(Also this question and photo came in from one of our readers via twitter and makes for a great example. Remember if you have certain questions on shooting, post production or anything else let us know, this site is for you!)
Here we have a photo of a family on the beach around sunset. The background is exposed pretty well but as you can see the faces here are very dark. The first step we always do when working in photoshop is create a duplicate layer so we can work on a copy of the original in case we need to quickly start over. The first thing that we want to do is lighten up the faces, by using the dodge brush. I usually set it to about 20%-30% opacity and use a soft medium size brush to paint light back to the image. (for this example I used a bigger brush than normal just for time sake) You want to use a medium brush and zoom in on the photo so you only lighten up the face, not part of the background. Here is what it will look like after this stage (see because I used a brush that was too big and didn’t take the time needed you see a halo around some of the people). Take your time and do it slow to make it look perfect.
Then i’ll use the burn tool to make the background and foreground a little bit darker and more dramatic. You can burn in as much or as little as suites your style and taste. Remember its your art, while learning photoshop keep testing things out to see how you like a certain effect.
Now the exposure looks much better. But you will notice when lighting up a underexposed image it will produce some noise to the image and especially around faces look pretty bad. There can be a few ways to clean up noise, the first I will cover is using the reduce noise filter in photoshop. The first thing I will do again is create a new layer to work on. Create a duplicate layer and then run the reduce noise filter (change the sliders on this screen to fit your needs). Since this will try and fix the noise in the entire photo and we only want to fix the noise on the faces (reducing the noise will also reduce sharpness of the image and the background isn’t really that noisy so we don’t want to reduce the sharpness of the background). In the layer where we just ran the noise filter create a layer mask. Fill the layer mask with black and then with a paint brush set to white paint back over the faces. This will only apply the noise filter to the faces, masking out the rest of the photo. You can even paint black on the eyes or other areas where you want to retain sharpness. With a layer mask when you paint black it will mask out that layer and white will allow that layer to be seen. You can also use the gaussian blur filter instead of the reduce noise filter and follow the same steps above to get similar results.
Here is what the final would look like.
Since the reduce noise filter in photoshop works OK but not nearly as good as some other 3rd party filters, here is another option. We have used NoiseNinja in the studio for a number of years and really recommend it for situations like this. It is very customizable or if you just want to have it run on auto still does a really good job reducing the noise but also not ruining the sharpness.
Since you can’t see the detail of the noise in these small web versions here is a cropped version of before fixing the noise and after with noise ninja.
We also got some great questions last week sent in and will address all of these questions later in the week!