5 Ways to Lighten Dark Underexposed Photos in Photoshop

Accidentally shot an underexposed photo? Here’s how you can lighten dark shots using Adobe Photoshop.

We all shoot underexposed photos from time to time. If you're shooting in low-light or high-contrast conditions it can be unavoidable. Fortunately, it's easy to fix dark photos in Photoshop.

In this article, we take a look at five methods for how to brighten a picture. All of them are very quick, but some will give you more control over the results than others.

It sounds like a silly question---if your photo is too dark, it's underexposed. But if you're going to be editing by eye it's a good idea to calibrate your monitor first. A poorly calibrated monitor will make images look either too bright or too dark.

For more accurate results familiarize yourself with the histogram. This is a chart that shows the tonal range of your image, from 100 percent black on the far left edge of the x-axis, to 100 percent white on the right edge.

Ideally, you'd want a fairly even distribution of data across the entire histogram, although it does depend on the nature of the shot. If the data is bunched toward the left side of the chart it's often a sign that the image is underexposed.

The first four options we describe below can be applied directly to the image, or used with Adjustment Layers. We recommend the latter for most cases. It enables non-destructive editing, allowing you to tweak---or even completely remove---an edit later on.

Here's how you do it. Click the Adjustment Layers button at the bottom of the Layers palette. Then select the tool you wish to use, such as Brightness/Contrast, or Curves.

When you need to brighten a photo the most obvious place to start is to go to Image > Adjustments > Brightness/Contrast, or to select this tool on an Adjustment Layer.

Brightness/Contrast is a good, simple option to use if the overall image is too dark. The Brightness setting primarily targets the midtones, so leaves the darkest and lightest points of the image untouched.

Make sure the Preview box is checked, then move the slider to the right until the image is as bright as you need it to be.

Adjusting the midtones can sometimes have the effect of flattening an image, so you might need to bump the Contrast up a little as well to compensate.

Another setting you'll see just below Brightness/Contrast is Exposure. This may seem an obvious one to use when you want to correct a photo's exposure, but it isn't.

Where the Brightness setting targets the midtones, Exposure uniformly increases or decreases all the tonal values in the image. It will lighten the highlights by the same amount as it lightens the shadows. This can cause them to become clipped, turning them into solid white areas with no detail.

As such, the Exposure setting is best used to correct errors made in camera, or for very minor adjustments. Ideally, keep it for RAW files only.

When you're shooting in very contrasty scenes the darker areas will often come out underexposed. The Shadows/Highlights tool is a quick way to fix this.

Go to Image > Adjustments > Shadows/Highlights, or create a new Adjustment Layer. A dialog box will open and automatically apply the default settings.

There are two sliders. Shadows brightens the darkest parts of the image while Highlights darkens the lightest parts. With the Preview box checked drag the Shadows slider to the right until the details in the darker areas of the image are at the level you like.

Move the Highlights slider as well, if you need to. This is a good way to reveal extra detail in brighter areas, such as a bright sky.

For additional help, take a look at our guide to removing shadows from photos.

The first two settings we've looked at enable you to adjust your image by eye. The next two let you make more precise corrections based on the histogram.

Both are still very easy to use, and they're very effective when you need to brighten a dark picture.

Levels is a tool for controlling the tonal range and colors in your image. Open it by pressing Ctrl + L on Windows, Cmd + L on Mac, or apply it on an Adjustment Layer, as we've outlined above.

The main part of the Levels screen is the histogram with three sliders positioned beneath it. The left and right sliders set the black and white points in the image, respectively.

We're concerned mostly with the middle slider, which affects the midtones. Simply click and drag the slider to the left to brighten your image.

If the brightest parts of the image are also underexposed, brighten them up by dragging the right-hand slider to the left. Try and position the slider in line with the edge of the right-most group of pixels in the histogram. Don't go too far---anything to the right of the slider will be 100 percent white, and contain no detail at all.

There's a lot more to the Levels tool. Check out our introductory guide to Photoshop for more detail on how you can use it as part of your everyday workflow.

Curves is similar to Levels, but gives you even more precise control over the tonal range of your image. It's an integral part of image processing in Photoshop, and is extremely powerful. Yet for a quick exposure tweak it's very easy to use.

Open the Curves tool by pressing Ctrl + M or Cmd +M, or open it on an Adjustment Layer.

As with the Levels tool, Curves is based on the histogram. This time, instead of sliders, there's a diagonal line that you need to manipulate to adjust the tonal range of the image. The left end of the line represents the shadows, and the right end represents the highlights.

To brighten the image, click on the line and drag upwards. If the image is generally underexposed, then you should be able to click somewhere near the middle of the line.

If you're trying to brighten the shadows then choose somewhere around 25 percent from the left. Try and pick an area where there's a large amount of the data on the histogram.

The beauty of the Curves tool is that you can repeat this process as many times as you need to. If brightening the shadows causes the highlights to become too bright, then click around a quarter of the way from the right edge and drag down to darken them again.

Each click adds a new point to the line, which is now a curve. To remove any points you don't need, select it and hit Backspace.

Our final way to brighten up your underexposed photos is to use layers and blend modes (how to use the blending mode in Photoshop).

Duplicate your image layer by hitting Ctrl + J or Cmd + J. On the new layer set the blend mode to Screen. The image will immediately be brighter.

If you want more, you can create as many of these extra layers as you need. Fine-tune the effect by lowering the opacity of the top layer.

The blend mode method is quick, easy, and flexible. It works well on fully underexposed images, and is also great for making local exposure tweaks. You could use Masks, for example, to select specific areas you want to adjust or protect from your changes.

Brightening up an underexposed image can sometimes leave it looking flat or washed out. A few final tweaks will fix this.

Use the Brightness/Contrast or Levels tools to boost contrast and give your image a bit more punch. Next, use the Vibrance or Hue/Saturation controls to restore a little of the lost color, should you need to. You should now have a bright, well exposed, and great looking photo.

As always with Photoshop, there are numerous ways to do everything, and it often doesn't matter which approach you choose. Just pick the one that you're most comfortable with, or that gives you the control you need.

Fixing exposure is only one of the many things you can do to improve your shots using Photoshop.

Image Credit: Dreamer4787/Shutterstock