Originally posted by T_MB I apologize if this is a silly question. But can someone describe for me the advantage of using the AF button rather than using the shutter/focus function? I see people mention it allows you to focus and recompose---but you can do that with the focus/shutter coupled by using focus lock.
Not a silly question - but one that has been discussed at length here.
From my perspective -
De-coupling AF from the shutter button simply allows for more control over your camera, it also puts the photographer into the same situation that we had for all those years before AF was introduced. Meaning - the act focus/compose/set exposure are separate acts - independent of each other. Where with the "default" mode the focus/compose/set exposure is set to where every time you press the shutter button - focus is forced. If you shoot like I do where I spend most of my time composing the shot rather than focusing.
For instance - I have said this before - shooting a Baseball game.
You are on the first base side shooting what you think will be a play at third. So, you warm up the camera (run finger over the shutter button to turn the electronics on) and focus (push the AF button until focus is achieved) on third base - where the "action" will take place. (Assuming you understand Baseball and the given situation). You meter off of the chest of the third baseman and lock the exposure.
The play commences - you fire off three quick shots, but the runner slides beyond third base - after you have your three shots. You have removed your finger from the shutter button. You fire off three more shots as the runner is tagged out.
Now if you had
NOT de-coupled - those last three shots would have been most likely missed while the
CAMERA decided what to focus on. The third baseman, the runner or someone in the crowd 100 feet behind the bag.
Could you have done this by using the AF button to turn off AF? Yes, but
I prefer to tell the camera what to do and when to do it.
I do not want the camera to do the thinking for me. If you do not de-couple AF, then the
CAMERA is making the decisions - not the photographer.
For me, it basically comes down to who is in control. Now AF will focus faster than I would/could back in the manual days. That is why I use AF most of the time - but the camera focuses on what
I tell it to when
I tell it to.
Most of the images I miss are because I get lazy and let the camera do the thinking.
The Elitist - formerly known as PDL