Last time I wrote a post about this topic I posted a video by Joe McNally and his Da Grip. This is really important technique and you should get used to use it and really make sharp images. Today I’d like to tell you about something different. This is a technique or setup what I use and it is absolutely subjective. You don’t have to do it the same way how I do it, just give it a try and you will see if you like or not. Without it you cannot say it.
Use back focus button instead of focusing using shutter release button. This topic was discussed in a podcast and Scott Bourne has his opinion why should he press one button extra (the focus button) when he still needs to press the shutter button to take the picture. How I said someone likes it, someone doesn’t. But I cannot imagine focusing without using back focus button. Here are some reasons why.
I’m a Canon shooter and factory default settings for my Rebel XSi (450D) was to focus and lock down exposure by pressing the shutter button half way down. When you are shooting in One Shot mode (AI-Single), then the camera had to focus first and than it will take picture. But imagine you have a bit trouble with focusing and with my L glass 70-200 f/4 you can have it on M/A, let camera do the focusing and if you need to than you can adjust it manually. But when you want to make another shot camera will refocus and you will need to adjust it manually again to get the focus where you want it to be. With back focus button setuped it will be individual, you can focus and you can take shot anytime you like.
Another reason for this is when you are shooting some action or sports. Cameras have buffers. Buffer is space in camera where images are stored until they are transfered to cards. And buffers have limits. For my XSi it is 6 RAW files or 9 JPEGs. When your buffer get full you need to wait until it makes some space and for that time camera will not shoot. Some photographers like to release the shutter button to give camera time to empty this memory and write it all down to SD or CF card. But when you will release your shutter button, your camera will stop focusing. And that means you will need more time to focus after the buffer is empty to get sharp shot. With back focus button, you can still hold it and the camera will keep focusing. Then you just have to press the shutter.
Another great thing is with default setup you locked exposure and camera started focusing. With setting up back focus button, you will leave your shutter button just with exposure lock and that gives you more creative options and possibilities.
These are two great advantages of using back focus button and I got really used to it. I don’t focus anymore by shutter button and that is the way it is. But it is really up to you if you like it or not.