My thought was that I suspect that I'm much better at determining whether I need continuous or single autofocus modes than the camera is... so I don't use it
It has been my experience that AF-A is generally best avoided as you know better than the camera what focus mode you want for what subject and switching between AF-S and AF-C is not that hard. AF-A will often cause a lag as it switches between single and continuous modes and this could cause you to miss a shot. Don't own a D7100 (D7000, D90, had a D300, etc.) but this should hold true for all DX models.
Simply put, AF-A is not worth it as it takes away control from you, the shooter, and you can manage these settings better yourself in most all situations. As a serious shooter, or even a semi-serious one, you should want more control, not less. I'm not against auto functions, as sometimes they can make sense, for example I often use auto iso within limits I define, and it works out well when appropriate, but I have found no appropriate time or place for using AF-A. Just my thoughts, but I think this is a commonly held view amongst many here if I dare say so.
Also, As a dedicated full-time user of the AF-ON function on my D300 and D700 I found I was having all sorts of problems with the progammable AF-ON mode in the D7100.....constantly missing focus on shots, especially when tracking moving subjects....... Then I discovered that Nikon has changed the AF-ON programming in the D7100 so that it is ALWAYS in release priority mode. Well, rats. Now I have to remember that I shoot the D700 one way, and the D7100 another way....ended up putting a piece of tape over the D7100's AE button to remind me that it wasn't an AF-ON button.
Genes Home wrote:
Agree with Trenchmonkey and MP79.
Also, As a dedicated full-time user of the AF-ON function on my D300 and D700 I found I was having all sorts of problems with the progammable AF-ON mode in the D7100.....constantly missing focus on shots, especially when tracking moving subjects....... Then I discovered that Nikon has changed the AF-ON programming in the D7100 so that it is ALWAYS in release priority mode. Well, rats. Now I have to remember that I shoot the D700 one way, and the D7100 another way....ended up putting a piece of tape over the D7100's AE button to remind me that it wasn't an AF-ON button.
Thanks for the heads up Gene. I did not realize this and have been doubling up on the AF - ON button hits to be sure it was hitting focus sometimes as I was finding the occasional missed focus. I had assumed it was me getting the wrong thing in the AF area, so was doing a second press just to be sure. What is funny is that I had set the priority to focus on both AF-C and AF-S believing it meant just that.
Why this stupid change? Reminds me of the way they changed the auto ISO feature as it relates to flash use.