Frames in Focus

How to Take a Good Picture in The Dark

Understanding the exposure triangle does require delving into some more technical aspects of how a camera works, which may not be entirely relevant for those of you who use phones for photography, but it can be interesting to understand, so I would recommend bearing with me.

Exposure Triangle

Aperture

Aperture is essentially how wide open the lens is, or how much light is let in. A wider aperture lets in more light, leading to a higher or brighter exposure, a narrower one lets in less light, leading to a lower or darker exposure. Aperture also affects a couple other things, but for the purpose of exposure how much light the lens lets in is all that matters.

Shutter Speed

Shutter speed is how long the shutter in front of the image sensor is open for. A very high shutter speed means that the image sensor is only exposed for a short amount of time, therefore not much light will be let in, resulting in a low exposure. A very low shutter speed means the image sensor will be open for a long time, meaning plenty of light will be let in, resulting in a high exposure. Again, shutter speed also affects other aspects of the photo, but for the purposes of exposure, it controls how long light is hitting the image sensor.

ISO

ISO is a little harder to explain. It’s essentially fake light added to the photo, which directly affects the exposure of the photo, so a low ISO adds very little light to the photo, and a high ISO adds more light to the photo; however, a high ISO also adds grain, or blurriness, to the photo.

Properly Exposed Photos

For a well lit photo, there must be a balance between aperture, shutter speed, and ISO. ISO is somewhat independent of the other two, so it’s easier to just think of balancing the other two. Too much light let in either by too wide an aperture or too low a shutter speed will result in an overexposed picture that is too bright, and too little light let in either by too narrow an aperture or too high a shutter speed will result in an underexposed picture that is too dark.

There is, however, one more factor to consider in relation to the exposure triangle, and that is, of course, how much light is actually entering the lens. If you have both a narrow aperture and high shutter speed, but you’re taking pictures of snow on a sunny day, you may still end up with an overexposed photo. This can be fixed by something called a neutral density filter, which is kind of like sunglasses but for a lens (or if you’re using a phone actual sunglasses!). Likewise, even if you use a wide open aperture and the longest possible shutter speed to take landscapes at night you may still end up with an underexposed photo. A dark photo can be fixed by increasing the ISO, but if it’s too high the photo will end up grainy and blurry. This is why you want the subjects of your photos to be well lit in the first place, so that you can just focus on balancing the aperture and shutter speed.

Back to Low Light

So what does that all have to do with low light photography? Honestly, not a ton if you’re using a cell phone or a camera on automatic settings, as the computers inside will work out all of those settings for you; however, it helps explain a lot of the issues with low light photos.

To take a well lit picture in the dark a camera needs to have either a really wide aperture so that as much light as possible can enter the lens, a really slow shutter speed so that there’s plenty of time for light to hit the image sensor, or a high ISO setting to artificially brighten the photo.

Settings Tricks

If your camera doesn’t have a low enough shutter speed to get a fully exposed photo it will result in the ISO setting being very high, which will result in a grainy picture. This is a harder problem to solve. Really all you can do is manually lower the ISO, which will give you a darker, but not grainy, photo, and then later brighten it using editing software. This is probably easier to do on an actual camera than a phone, but most phone cameras have some sort of “pro” mode where you can manually change the settings. It is always easier to make a picture brighter afterwards than darker, so when in doubt, take an underexposed photo.

Another setting you should definitely turn off on your camera is the flash. Flash photography could be an entire article, but the short version is, unless done properly, it usually ends up in very harshly lit photos that don’t look very good. It’s better to take a darker picture and brighten it later then have a very harshly lit one.

Hopefully you made it to the end of the article and found some helpful tips for taking photos in the dark. Happy photography!

A Note from Owen, Frames in Focus Columnist:

Complete beginner looking to try a new hobby, amateur photographer looking for some tips, or total pro in need of something new to experiment with? This is the column for you! Every issue will feature a new batch of tips and tricks, with something interesting for every skill level, as well as a submissions section for you to share your work.