Sometimes photographers will deliberately underexpose or overexpose their photographs to create a desired effect. However, other times an otherwise good photo will have been ruined by improper exposure. This guide will walk you through the process of correcting incorrect exposure levels with Photoshop.

Things You Will Need

Photoshop (I use CS4 but any version should be fine)

Step 1

Underexposed Photos

Correcting an underexposed image only takes a few quick steps. However, you may find yourself tweaking and adjusting the photo until you have the exact exposure that you want.

Underexposed Soldiers
"Mmmm" by user Ian Munroe from Flickr. Original URL

The first step is to create a new Exposure adjustment layer (Layer>New Adjustment Layer>Exposure) and a new Brightness/Contrast layer (Layer>New Adjustment Layer>Brightness/Contrast). Increase the Exposure and Brightness levels and decrease the Contrast until you find a combination that you like. Experiment with high Exposures and low Brightness and vice versa to familiarize yourself with the slight differences between increasing the Exposure and increasing the Brightness. Keep an eye out on the blue carpet on the right-hand side of the picture, as increasing the Exposure too much will result in a certain spot becoming far too bright and unnatural looking, ruining the image. For this image I ended up settling on these values: Exposure;+1.29, Brightness; 150, Contrast; -50.

Grainy Soldiers

At this point you should have a nicely lit up image. However, as a result of correcting the exposure, you'll notice two problems. The first problem is that, as we can now properly see the image, we can notice that the photo has grainy elements on the left-hand side. The second is that the image is slightly too warm (it has a yellowish tinge).

For the graininess we're just going to use a quick fix to make it unnoticeable. Select the Blur tool with a medium size brush and set it to a low opacity (around 25%). Carefully blur all the graininess out of the image, taking care not to blur other parts of the photo. You may have to care over certain areas more than once. You'll notice that this isn't a perfect fix, but for this photo we only want to make sure that the viewer's eyes aren't immediately bothered by the large grainy patches.

For the second part, we're simply going to add another adjustment layer: a Photo Filter (Layer>New Adjustment Layer>Photo Filter). In the Photo Filter select a Cooling Filter and adjust the Density level until the image looks right. I chose a Density level of 10%.

At this point you should look over the image for any final adjustments you want to make. I ran over the soldier's bodies with the Dodge tool (set to Midtones, 14% Exposure) to brighten their features a bit more. You should now have a perfect image that you created out of a barely visible photo!

Soldiers Final (22600)

Step 2

Overexposed Photos

For images that are overexposed, we're going to try a different method.

Dogs - Overexposed
"Shyleigh & Penny 1/2" by user shouldbecleaning from Flickr. Original URL

In this photograph, we can see that overexposure has caused a lack of detail and an overall faded look. To correct this, we're going to create a Levels adjustment layer (Layer>New Adjustment Layer>Levels). Selecting this level, you should see a histogram displayed in the area above. Levels Histogram (22962) This histogram displays the distribution of brightness throughout the image. The left side displays the level of black and the right displays the white. As we can see from the histogram, the left side is clipped off and the right side has a sudden peak at the end, which matches up perfectly with what we see in the image.

To adjust the levels, we're going to drag the midtones slider (the gray one) and start dragging it toward the right. You should now start to see color and contrast appear in the image. Be careful not to drag the slider too far to the right. When you reach the desired point, simply let go of the slider and you're done.

You can also use this method in reverse for underexposed images. Remember to always use adjustment layers instead of altering the layers themselves. This way you can always go back and alter the image without losing the original values.

Dogs - Corrected (22961)


Tips & Warnings

Sometimes an image will be so overexposed or underexposed that areas on the photo have turned to pure black or white. In this case, those areas are beyond recovery and nothing can be done to fix them (well, at least using the tools mentioned in this tutorial). However, this doesn't always mean the photo is ruined. If you look at the overexposed dog image that I altered above, you can see that the right-hand dog is actually purely white. However, you probably didn't notice this when you glanced at the image before because your mind auto-corrects it to make it fit with what it should look like. In this case, the image is close enough to looking natural that the mind can make the leap and register the picture as normal. Of course, this won't always be the case and sometimes these pure white or black areas can totally ruin a picture.