Monday, October 22, 2012

Using the back button for focusing

This post is specially dedicated to Thomas B. 

For low light shooters, nothing’s worse than having an autofocus lagging and unable to lock constantly on the same spot where you’re aiming. When shooting sports, you don’t want your AI Servo mode being disoriented by another player coming in front of the one who you were following. In both cases, it would end in a missed shot.

Why am I talking about it? Well, there’s a solution. 

Deeply hidden in the custom functions, there’s an option allowing not having the autofocus command (aka a half press on the shutter release) and the shutter release itself. It means that if you lock once on your target, and if it doesn’t move (a speaker for instance), you can take as many pictures as you want by simply pressing the shutter release, without having to deal with the half-press thing. In most cases, you’ll lift your finger too much and you’ll have to lock again before being able to take the picture. 

An EOS 1D mark II and its back buttons 

Same situation with our football player; the AI Servo mode is constantly searching for any movement of your target but it’s not always perfect when the subject remains static. By searching back and forth, it will blur your picture at least for half a second… just when you’ll have to take the picture. With the back focus button, press only once, and when the player is in focus and stands still, you don’t risk losing your focus point. In other situations, when you work in “action” situations where you have to shoot at arm’s length, you know that by using a small aperture you’ll have what you need in focus, and everybody knows that focusing in that kind of situation is just impossible. So prefocus and then don’t worry, shoot, your camera won’t freeze by trying to lock on something constantly moving.

You may need a few hundred shots to get used to it but it’s totally worth it, especially for low light shooters. You’ll save dozens of shots and these are the ones that will make the difference at the end of the day (or night). So, try it, you won’t be disappointed. I've been using it for a year now and it's one of the first things I set when I'm working with another camera.

These CFn are available on all professional Canon cameras (1D and 5D, maybe others as well), so as on their Nikon equivalents (AF-ON buttons I think).

The CFn menu of my 1D mark II

Thanks for reading.