Underexposure occurs when a photo appears darker than reality because not enough light reaches the sensor through the shutter. This can happen for a variety of reasons, including the wrong settings for your shutter speed, your aperture and your ISO. On a digital camera, you can look at the image on your screen and adjust your settings as necessary to allow more light in, or you can create more light in the scene, but sometimes the moment comes and goes too fast to fine-tune.

Underexposed images aren't all bad, so if your photos come out underexposed, don’t panic.  First thing’s first: Can you lean into it? Sometimes a darker image is intentional, if the photographer is going for a moody or dramatic feel. Purposely underexposing your images may even help you develop a new photo aesthetic throughout your body of work.

Typically, it’s easier to fix underexposed photos than overexposed ones (where the image is too bright and portions are blown out) because sensors in modern digital cameras are better at capturing details in the shadows than the highlights. That means when you lighten an underexposed image, the detail and visual information is still there in the dark areas. Whereas  darkening an overexposed image is more problematic, because the detail and information in the brightest spots isn’t there to begin with. 

If you’re shooting digital and notice everything coming out darker, here are a few reasons why it might be happening, as well as the steps to fix it. 

Causes of Underexposed Photos and How to Fix them in Camera

There are two main causes of underexposure: the available light in your shot, and your camera settings. Anything that increases or decreases the light in the area you’re taking a photograph will impact the overall exposure of your images. This can be as small as an open curtain on a window, or a model wearing a white shirt. When shooting outside, a single cloud covering the sun will dramatically change the exposure of your image. 

Some of these things are within your control, so pay attention to every light source, including reflective surfaces. If these things are not in your control, or you’ve already done all you can to adjust the light, turn to your camera settings for the answer. Now it’s all about the exposure triangle, meaning the shutter speed, aperture, and ISO of your camera.  

• When you go to take a picture, the light meter in your camera typically takes an overall reading of the frame and gives you the average exposure, so if there are really bright areas like snow on the ground or a white sky, that will throw off the reading from the light meter. The meter picks up the bright spots and thinks the scene is lighter than it is, so it will suggest an exposure that might cause other areas to be too dark. Most cameras have a “spot metering” setting, where you can focus your light meter on a specific spot in the frame to get a reading, which might get you closer to the exposure you’re aiming for. 
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• For tricky scenes that have a lot of contrast, plan to underexpose the image slightly (a few stops down on your aperture or up on the shutter dial) so that there’s enough information in the highlights. It might look muddy on your camera, but it will be fixable when you edit. 
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• When your f-stop (aperture) is too small, not enough light will get to the sensor, which will lead to underexposure. Apertures follow the format of f/2.8, f/4, f/8, but because that actually represents a fractional size of 1 / 2.8, 1 / 4, and 1 / 8, the smaller numbers mean a larger hole. So f/2.8 lets more light through than f/8.
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• Shutter speed refers to the amount of time the shutter is open and allows light to pass through to the sensor. Fast shutter speeds can underexpose an image because not enough light passes through. Slow shutter speeds will allow more light to go through, but if it is much slower than 1/250 of a second, you have a higher chance of a blurry image. If you use a slow shutter speed, consider bringing a tripod or stabilizing your camera another way in order to avoid unwanted blur or shake. Similar to aperture, the format of shutter speeds is fractional, so it’s 1/30th of a second, 1/60th of a second, 1/1000th of a second, and so on. Higher numbers mean faster shutter speeds.

• ISO is the sensitivity of your camera’s sensor to light and is a setting that can be changed quickly and easily. The higher your ISO is, the more sensitive your sensor is and the brighter the image will be. If your images are coming out underexposed, consider bumping up your ISO. The tradeoff here is that a higher ISO can create more noise in an image, so it might look pixelated or lower quality. “Noise” refers to a visual distortion present in low-light photographs, that looks like splotches and discoloration. You can reduce the risk of noise with lower ISOs.
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• Dark backgrounds with light subjects can impact a light meter’s ability to get an accurate reading for balanced exposure. Take the moon, or a singer at a concert as examples.  The light meter is attempting to balance between the light subject and darkness behind them, which throws off the exposure reading. When exposing for situations like this, there is no right or wrong way to do it, because photography is art and art is subjective, but adjust your settings until you find the exposure that most accurately represents the look you’re going for. 

How to Edit an Underexposed Photo

There’s no shortage of ways to fix an underexposed photo, both in the moment of getting the shot and afterwards when you’re sitting at your computer. During the shoot, it’s worth checking the histogram on your camera to make sure there’s a relatively even spread of light and dark areas. Your histogram will never be perfect, but adjusting your settings to avoid the high spikes and low drops can give you a good starting point. If you’re done shooting, don’t worry, software can help.

Lightroom and phone apps like Snapseed offer a tool called the exposure slider. When you slide left, it dials down the exposure and the image gets darker. Slide it right to increase exposure and lighten the image. You might find that a slight adjustment here makes a huge difference! 

Editing software also has sliders for highlights and shadows, where you can isolate changes to the exposure of the lightest (highlight) or the darkest (shadows) areas of your photo. This is useful for underexposed images where the highlights are balanced, but the shadows are too dark. You can keep the integrity of your highlights while you adjust your shadows. 

Masks and graduated filters are another (slightly more involved) tool in many editing programs. Masks let you choose a specific area, like the background, sky, or subject of the photo, and dial the exposure up or down in just that spot. Another type of mask is the brush tool, where you can run the brush over a specific spot in the image to raise or lower the exposure. Many editing programs have AI features that automatically read where the sky or subject is, so you don’t have to spend a ton of time going over them with a brush.

Graduated filters do a similar thing to the mask but cover a broader area, and they have a gradient built in where the new exposure settings are stronger on one end and gradually lessen over the length of the filter. So you might have the exposure dialed down 2 stops at the top of an image, and by the bottom, there’s no change to exposure. This can be great for adjusting the exposure in a way that looks natural and avoids looking over-processed.

The moral of our story is: underexposure is not only easier to fix than overexposure, it can be an intentional aesthetic – one that adds depth, dimension, and feeling to a shot.  Did you enjoy our guide?  Subscribe to the SmugMug blog and get more just like it!