I have read so many times from other photographers during my journey to learn back button focus, about how it was one of the biggest skills that changed their photography forever and helped them grow significantly. I have also read just as many photographers words about how they just can’t get it and how they gave up and stuck with what they knew. Why does back button focus (BBF) have to be so difficult? I am going to try to explain how I finally “got it” in my terms, simply. I am not saying it is right or there isn’t more complexity. All I’m saying is this is how BBF works for me. I will also say I shoot Canon so I’m writing about the brand I know. Nikon works in much the same way and you should be able to customize this by reading your manual or just searching other tutorials on BBF that are related specifically to Nikon.
What exactly is BBF? It is the ability to separate the focus from the shutter button by using your AF-ON button. You may ask, why should I try out BBF and what advantage does it have? BBF gives you more control over your camera and can ensure you are more likely to get your subject in focus, and ultimately that’s what we all want, right? BBF works well when shooting at wide open apertures and also when tracking a moving child. It also allows you to recompose and keep focus where you originally set it. I find this to be beneficial when composing for the rule of 1/3’s because not only do I not have to keep continuing to toggle my focus points, I also can use my most reliable and sharpest center focal point. This comes in especially handy to me when I am using a fixed focal length lens.
It also serves me well when shooting a child or other moving subjects. I can just hold the BBF button down and it will track the child, etc. and constantly refocus. Then when your subject stops you can recompose and take the shot. Presto, it’s in focus even if you recompose as long as your subject didn’t move from the time you released the button.
- First, BBF is best used in AI Servo mode so I’d suggest changing your settings if you normally use One Shot Focus (which I do for a lot of things). Then you can activate BBF via the instructions below for a Canon.
- Second, go to your custom menu then choose C.Fn IV-1. Choose one then press set. From there you can choose a variety of options that control how your camera meters and functions. You can research all of these if you like or look up tutorials. Personally I use option 2 because it seems to be the truest form of BBF to me.
- 2: Metering start / Meter + AF start:
The shutter button no longer activates auto focus, but still fires the shutter. Auto focus is activated solely by pressing the “AF-ON” button. There’s no locking of exposure, unless you separately press the “AE Lock” button. I shoot in manual and am constantly setting my exposure so this is what I want. I don’t want it to be locked. If you shoot in other creative modes a different setting may be best for you.