A lot of people like to use a separate button to focus and just use the shutter release to expose the scene and take the shot. This can be done fairly easily by setting the AEL/AFL lock to AFL, but it then disables the ability to AEL lock, which can be handy in many circumstances. Once set this way, you can assign any, or any number of buttons to AFL, but you can't get back AEL. However, there is a way that gives you almost the same effect and is maybe even better. If you go to the menu/gear/(button/dial/lever)/button function setting, you can select any button to act as the manual focus switch. I've assigned what was the depth of field preview button next to the lens as this switch, as it's out of the way and so can't be accidentally pressed when the camera is turned on. How it works is that when you press the shutter half way, release the shutter button and then press the assigned manual AF button, the focus stays locked at that point until you once again press the assigned manual AF button to enable S-AF. It's not quite as quick as assigning AF the other way, but you rapidly get accustomed to this method and it ends up being just as effective. An additional benefit of this method is that you retain the AEL lock function, for situations where you don't want the exposure to change, such as panoramas. You now have the ability to set the focus and exposure to stay fully locked in any circumstance. This method also allows you to quickly go from a 'back focus button' style of shooting to normal shutter button shooting, without any menu changes. I haven't seen this mentioned before, so thought I'd pass on what I do. This works with the E-M1 and I presume on all of the O-MD models.