When To Use the Back Button Focus On My Canon Digital SLR

For those people not familiar with what the back button focus is, it’s a feature on Canon Camera’s where a button on the rear of  the camera is use to focus by using your thumb instead of the shutter release button. This back button focus separates metering and focusing from the shutter button and have the shutter button dedicated to metering and releasing the shutter to take the photo.



I’ve been slowly practicing using the back button focus on my cameras, and I can say that it can really work at times, I just need to use it more and more to get accustomed to it. The best thing about it is that it separates the focus activity from the exposure. Once I have my subject in focus, I can then recompose and take the shot.  All I need to think now is the exposure which happens when I press the shutter.

Now going back to the question, “When Should You Use The Back Button Focus?” It depends, I use it mostly when I’m shooting macro and landscapes, sometimes I also use it in taking portraits. Some people I know use it all the time instead of using the the traditional all in one shutter button. If you are familiar with it I don’t see any reason why you can’t use it. I’m still trying to get the hang of it. My muscles and coordination still looks for the traditional shutter release button, but once in a while I love to using the back button, it has it’s pros and cons.


  • It takes practice to get use to.
  • You have to enable it in the Function section of your camera
  • For starters, it requires a little bit of patience
  • In rare cases where you need to shoot using one hand, it very hard,  especially when using a long lens.


  • Easy to recompose shots with out loosing focus.
  • Really easy to lock focus.
  • Very convenient feature to have when shooting macro.
  • Great to use on moving subjects like birds.

How to enable the Back Button Focus?

It varies from camera to camera, some cameras like the 40d, 50d, 60d & 7d is equipped with the rear AF-ON button, which is really easy to press with your right thumb on the back of the camera, all you have to do is go to the Custom Function on your canon eos dslr, it is found in Custom Function Group IV, Setting 1, mine is set at option 1. There are various options available within that menu. On other Canon cameras this option are found under Custom Function IV or C. Fn IV:Operations/Others, on my rebel, i set it to option 1.

It’s a great feature to have and I suggest you give it a try. At the end of the day and you don’t feel like using it, you can always go back to the Custom Function and disable it.


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