Focusing in Low Light

In this pro tip, you’ll learn how to focus more easily:

Get Crispy Sharp Images in Low Light

Getting that clean, crisp focus is hard enough during the day let alone at night when your camera seems to just be trying to find anything at all to focus on. The camera needs to be able to see in order to focus and if it can’t tell the difference between your subject and the background, it is likely to just keep rotating back and forth.  Now there are a few work arounds and everyone has their technique that works for them.  The first, and sort of most obvious, is to add more light, either using a flash or moving a light closer.  Now, this might of course defeat the ‘look’ you are going for but just had to say it.  What are your other options though?

First of all, let’s talk settings.  Using a higher ISO but not so high that it is going to add a bunch of digital noise to your image is important.  For most cameras today, this is around 6400 ISO.  From there, using a fast lens, something like f/2.8 is good but f/1.4 is quadruple the amount of light.  That being said, you are also making your depth of field incredibly shallow and thus harder to get focus.  Lastly, picking the right shutter speed, anything below 1/60th can lead to some motion blur from unsteady hands or anything moving in your frame, which can be misinterpreted as being out of focus.  Once you know what settings you are using, how do you get it in focus?

One of the easier options is to use a flashlight like the one on your phone, illuminate your subject so your camera can get focus, turn off the flashlight and snap the photo.  Now this might require an assistant depending how far away your subject is or having your subject point the light at themselves.  This can be a problem of course if your subject is moving or if you aren’t using a tripod.  Moving even an inch when shooting with a lens faster than f/2.8 can mean losing focus.  This is also a great time to use back button focusing, which if you haven’t already learned about, check out our other article about it!

Another trick, which to be honest is more of a skill, is to switch over to manual focus.  While it does take a bit more time and can strain your eye a bit, with time, it’ll become second nature.  Many times, I will use the focus magnifier option on my Sony which zooms in when manually focusing, a move way too close and slowly turn my focus farther away, eventually I hit a spot that seems to be in focus and then I go just a bit past it, make sure it won’t get any more in focus and then pull the focus back until it looks crispy again and take the photo.

Some cameras also offer ‘peaking’ when using the back LCD screen which adds little dots to whatever is in focus.  This can be useful at times but sometimes misleading with low light or extremely shallow depths of field so be sure to test your camera to see how accurate it actually is.

Some external flashes and even cameras will have something called Focus Assist which shoots out a bright light or a red, infrared light grid to help your camera focus.  While the white light can be bit bothersome for your subject, the red light wont blind them at least and calls less attention to you as a photographer.  Some external flashes and cameras will require you to use the Focus Assist only when using the flash but some, typically higher end ones will allow you to use it both with or without the flash.  You can of course just block the flash by putting something over it but make sure you fully cover it cause just a little light spilling out can ruin your image, or be a great creative mistake!  This can also be an issue if you are trying to be sneaky because the infrared or burst of light will definitely catch your subjects attention.

All in all, focusing in low light is a tricky thing and really dependent on the situation.  Try learning manual focus, using a flashlight to help your autofocus or invest in an external flash that allows you to use the focus assist and not the flash.  All will help you hone your skills as a photographer and with some practice, you’ll be nailing focus with minimal light in no time.

Continue to lesson 33: What is bokeh?