Some reader’s questions enlightened me to the fact that I didn’t have all of the necessary information in this post, so I’ve tried to rectify that. Sure hope it helps. 🙂
“Back Button Focus” refers to a way to engage autofocus (AF) on your camera separately from the shutter button, and is the preferred technique for many photographers. The big benefit (for me) is that it allows me to stay in Manual Focus (MF) while retaining the capability to AF if I want to. In practice, it allows you to use AF and then automatically revert back to MF so you can refine if necessary. Then, you can expose, compose, and shoot without worrying about the focus changing when you take the shot. Plus, it enables you to tweak the focus if necessary. It’s also handy in the studio, so you can focus on your subject and then not worry about possibly changing the focus point every time you press the shutter button.
The beauty of the way I set up my E-M1, is that with just a flick of the Lever, I can easily get back to full AF with the shutter button. So here’s one way to do it … there are probably others. Go into the Custom Setup (Gear icon) – Menu B (Button/Dial/Lever) – Lever Function and set it to Mode 5. The first 4 modes essentially change which dial or button is used to change WB and ISO. I prefer to do that in either the SCP (Super Control Panel) or set my Right and Down Arrow Keys for those functions.
There are also two other settings required for this to work. First, you must keep the AEL/AFL Button configured to AEL/AFL: Custom Menu B – Button Function – AEL/AFL Function – AEL/AFL. Second, go to Custom Menu A – AEL/AFL, press the OK Button, select MF and press OK again. Now, set MF to mode 3 and press OK one more time. If you also like using Back Button Focus when in S-AF, then set S-AF to mode 3, also. BUT, if you set S-AF to mode 3, you lose the AEL functionality of the AEL/AFL button when the lever is in position 1.