8 low light focus tips
The world looks a little different and a whole lot more interesting through the lens when the light is low. So low light photography can be very rewarding, but of course comes with its own set of challenges. The first one being how can your camera see well enough to focus in low light?
More specifically, when you’re photographing in low light it is often for the very characteristics that low light offers, so you don’t want to blast the scene with flash. So how do you shoot in really low light when you want to use a flash?
I’ve listed the processes that I would use in the order that I would use them, or at least think through before trying one. As you can see, I prefer to start with the simple low light focus solutions.
- Focus on a bright area
- Focus on the subject’s edge
- Use your camera’s inbuilt AF illuminator
- Focus using live view
- Back button focus
- Light it up with a flashlight
- Focus manually
- Use hyperfocal focusing
1. Focus on a bright area
If there is a brighter patch in the scene on the same focal plane as the part you want in focus, aim your focus there, lock focus and then recompose before taking the shot.
2. Focus on the subject’s edge
If you can make out the edges of your subject, it means that one part of the subject is brighter than another part. As your camera’s focusing system works by detecting contrast between light and dark, it will help to focus. Aim your focus point the the edge, lock focus, recompose and then take the shot.
That’s all fairly straight forward, but how do you lock focus?
How to lock focus
Before we move on to other methods of focusing in low light, here’s how I would go about “locking focus” in challenging conditions. Assuming your subject is not moving:
- Use single servo autofocus. For Nikon it’s called AF-S and for Canon it’s One Shot AF. In this mode, when you part depress the shutter button to focus, the camera will focus then hold it. If you keep holding the shutter button half way down and recompose your shot by moving your camera (while still on the same focal plane of course), the area you focused on will still be in focus. Once your image is compsed the way you want, push the shutter button right down to take the shot.
- If you use continuous autofocus, focus then switch from autofocus to manual focus and shoot away.
If your subject is moving, the AF illuminator, if you’re close enough to your subject, and live view are your friends. Which leads to the next focusing tip.
3. Use the AF illuminator
When it is too dark for your camera to see properly, it can’t focus and that’s when the AF-assist illuminator is useful if your subject is not too far away. It’s the light at the front of your camera that also doubles up as the self timer lamp and red-eye reduction lamp. It will shine enough light for the camera to see the subject and then be able to focus. You can set it using your camera menu.
When wanting to use the AF illuminator, be aware of where you’ve positioned your focus point. With some older cameras it had to be in the middle of the viewfinder. With newer models, this may not be necessary, but the focus point does still need to be near the middle. You can’t use the AF illuminator when the focus point is near the edge of your frame.
When is the AF illuminator useful for focusing in low light? Bride and groom’s first dance.
What if your subject is too far away for the AF illuminator to be effective?
4. Focus with live view
Your best option is to switch your camera to live view, because your camera’s autofocus works differently in live view. Without delving into the technical details of how focus works (phase detection autofocus vs contrast detection autofocus), live view uses contrast detection autofocus. So it’s more accurate in low light conditions and works in all areas of the frame, even at the edges. The only requirement is that there is enough light for the sensor to analyse the image.
Bear in mind that when you are viewing your scene with live view, rather than through the viewfinder, your camera won’t be well supported, as your arms will be outstretched. This will result in camera shake in your image, so a tripod is essential.
What would you shoot using live view for focusing in low light? Light trails from cars.
5. Back button focus
If you can lock focus using the tips above, back button focus is a good option for low light photography.
Like the shutter button, back button focus can be used in two ways. When you use back button focus with focus set to single servo / one shot AF, your focus will hunt until it locks. In continuous focus it will hunt, lock on the subject and stay with it, even if it moves (as long as your focus point remains on your subject of course).
Once focus is locked, simply depress the shutter to take the shot. Without back button focus, you run the risk of your camera trying to refocus before you depress the shutter.
Further reading on back button focus – Why back button focus is your BFF, and how to use it
When are you most likely to use back button focus? With moving subjects.
6. Light it up with a flashlight
I love a low tech, old school fix to problems. Enter the flashlight – and who doesn’t love playing with a flashlight?
It’s always a good idea to put a flashlight in your bag before heading out on a shoot that might be in low light conditions. Apart from ensuring that you don’t trip over stuff, it’s a really useful focusing tool. There are two ways that you can use it:
- Aim it at your subject, autofocus, lock focus, switch off the flashlight and take the shot.
- Place the flashlight in the scene to illuminate it, autofocus, lock focus, remove the flashlight from the scene and take the shot.
See, low tech is always simple and very often the solution.
What would you shoot using a flashlight to focus in low light? Still life or landscapes with focus on a still foreground subject.
7. Focus manually
Speaking of low tech. There is always the option to manually focus your lens. I think because we get so used to autofocus, we don’t think about using manual focus nearly enough. Low light photography is the perfect time for manual focus.
The first point to note before you do anything is turn off the autofocus to avoid damaging the autofocus mechanism by turning the focus ring.
Of course, as this is photography, there are options of how to go about focusing manually
- straight up manual focus
- zone focusing
The easy manual focus option
There’s the method that’s most obvious – set your camera and lens to manual focus, look at the subject through the viewfinder and turn the focus ring until the subject is perfectly sharp. Take the shot.
Zone focusing / scale focusing
Then there’s the less obvious way to focus in low light.
When you use the lens scale to focus manually, you are zone focusing, also called scale focusing.
Before I start, please note that not every lens has a lens scale. Particularly cheaper lenses. But that doesn’t mean you can’t zone focus.
What is a lens scale?
If you look at your lens you will see the infinity symbol (it looks like a figure 8 on its side) on one end of the scale. The other end of the scale shows your lens’ minimum focusing distance. The distances are written in both feet and meters. As you turn the focusing ring you will see that the numbers move around. The number resting in front of the alignment point is the distance at which you will achieve sharp focus.
As using the lens scale method to focus in low light relies on your ability to judge distance, use a wide angle if possible and a narrow aperture to give yourself some wiggle room – in other words, greater depth of field.
Tips for using zone focusing
To fully understand how to use the lens scale, you must first become familiar with how depth of field works.
Briefly, this is that depth of field extends behind your subject by 2/3 of the depth of field, or zone of focus, and also in front of your subject by 1/3 of the depth of field, or zone of focus. There are 4 variables that affect depth of field – aperture, focal length, distance and camera sensor.
Further reading on depth of field – Using depth of field for gorgeous photography composition
There are some great depth of field apps for your phone – I’ve got F-Stop Calculator on my iPhone. Also, here is a link to a really handy depth of field calculator: https://www.photopills.com/calculators/dof
Just having a play around with these calculators should help you to understand the variables of depth of field.
When are you most likely to use scale focusing / zone focusing in low light? Street photography.
8. Use hyperfocal focusing
I’ve listed hyperfocal focusing last, purely because it’s what I would use least as I do more portraiture than landscapes. Hyperfocal focusing is mainly for landscapes, or photographing from a distance.
The apps and website link above also have hyperfocal calculators to help you decide on your camera settings.
If something is far away from you, set your focus to manual, turn the focus ring to infinity and ensure that your aperture is set to the smallest setting possible. The acceptably sharp area of the image will be everything from half the hyperfocal distance through to infinity.
When are you most likely to use hyperfocal focusing? Landscape photography requiring front to back sharpness.
If you have any questions about how to focus in low light, let us know in the comments.
Also, we love good news, so if our low light photography tips have helped you to understand how to focus in low light, share that too.