Richard Barbour Asks Why Turn Off Shutter AF When Using Back Button AF?
I’ve had the G85 for a short time and enjoyed reading your review, especially the explanations of the various settings you use. I also like to use back-button focus, but not all of the time, so I was confused by your settings where you say to set “Shutter AF” to OFF. I have it set to ON, and back-button focus works fine when I use it, but otherwise, the focus will lock when I half-press the shutter. This lets me have it either way; am I missing something?
Richard, the reason I set “Shutter AF” to OFF is due to the fact that, yes, the back button will also initiate AF but having both Shuter Button focusing AND the Back Button Focusing, they negate each other. The reason we use Back Button AF is to separate focus activation from the shutter button. The reason for using Back Button AF is to be able to focus on a subject, recompose the frame since most subjects won’t appear directly behind the AF sensor. Now that you have focused on the subject and recomposed, the AF sensor may be far from the specific subject you want in focus. You have to push the Shutter button to take the photo and if you have Shutter AF-ON, it now refocuses on whatever the sensor is pointing at. By turning Shutter AF off you no longer have to worry about the camera refocusing AFTER you have focused on the subject you actually want. In short, having both Back Button AF on and Shutter AF-ON, they fight each other and completely negate the benefit of either one. Let me now if this is as clear as mud. I’ll try it gain if needed. Hope this helps. Sorry for the long delay in answering this.