Saturday, January 28, 2017

How To Focus Your Camera at Night

If you've tried to take a photo in the dark of night, you may have found your camera had a hard time focusing... or never focused at all.

Digital cameras focus by looking for contrast within the image. They are looking for areas where a bright part of the image is next to a darker part. This is why cameras focus best on sharp edges like door frames, building edges and so forth.

The problem with focusing at night is that everything is dark so there is very little contrast. This causes cameras to "hunt" for focus and often fail to lock in a good focus, resulting in blurry photos. My camera will often refuse to take a photo at all because it didn't focus.

Two solutions for focusing at night are:
  • Using a light to assist
  • Live view

Using a Light

If you have a light handy, you can use that to illuminate your subject and provide enough contrast for your camera to achieve focus. You can use a flashlight, your car's headlights, or even your cell phone to put a little light on your subject.

Once you achieve focus with your camera, put it in manual focus to keep that focus point and start shooting.

For the photo at the top of this post, I used my portable flashlight (which is ridiculously bright) to light up the signal tower.

First I put my camera on a tripod. Then I lit the signal tower up with the flashlight, and focused on the tower using my camera's auto focus.

Once it achieved focus, I flipped the switch on the lens to put it in manual focus and turned the flashlight off.

As long as I didn't zoom in or out, or change the location of the camera, the focus would stay "good" and I could take as many photos as I liked.

Live View

Another option is to use the "live view" feature of your camera. This is a feature of most DSLRs where it will show what the camera's sensor sees, in real time, on the display on the back of your camera. Normally when you look through the viewfinder, you are seeing a reflection off the mirror in your camera.

Live view has its benefits because it is brighter than the viewfinder, and you can zoom in. In the video below, recorded in Fargo, North Dakota, I used live view to focus on the clock tower of the Fargo train station.

The basic idea is this:

  • Put the camera on a tripod
  • Put the lens in manual focus
  • Turn live view on
  • Expand the live view as far as you can go
  • Use the focus ring on the lens to focus using the live view as a reference
  • Turn live view off and take photos

In this case I had the benefit of a relatively bright clock face, but it works pretty well in darker situations as well.

Live view really sucks the battery, so you don't want to use it long term.

This should work well for mirrorless cameras, where you are basically using live view all the time. I don't have a mirrorless camera so I don't have any personal experience of this.

I hope this helps you take some great night photos. Shooting at night is a totally different experience and I enjoy the challenge and the different perspectives it brings!

See Also


DaveM said...

What kinda of flash light do you have?


Jenn said...

Good advice!! I'm going to try more might shooting!

Canadian Train Geek said...

Hi DaveM, I was using the MotoMaster Eliminator 3.5M Series Spotlight (part #037-9464-6). I don't see it on Canadian Tire's web site any more. It has an LED light on one end and a bulb/spot light on the other. The spotlight can light distant tree tops up and is really bright (and hot). The LED light is pretty bright too.

Chris BIGDoer Doering said...

We have an older early 1990s knock-around lens that seems to be able to focus on anything, even in extreme low light, stars included. I thought this was the function of the camera alone, but this suggests the lens plays a part. Still, we bring along a day-lighter flash light. Ours is a small metal baton style that puts out way more light than one would expect given its size.

Canadian Train Geek said...

Hi Chris, that's surprising that a "knock-around" lens can focus that well at night! Which lens is it?

I have a couple of small made-in-China LED flashlights that are super bright as well. The larger of the two is very bright!

Chris BIGDoer Doering said...

An EF 28-80mm f/3.5-5.6 II, early 90s model, a lens that has a reputation for being lackluster at best, soft focus being an often heard issue. Mine is as sharp as a tack and its low light focusing is something amazing. Must have got a bad one. We picked it up for literately nothing and use it when we shoot in difficult dirty industrial environments. Places where if we break it, we won't cry.