Derrel
Mr. Rain Cloud
- Joined
- Jul 23, 2009
- Messages
- 48,225
- Reaction score
- 18,941
- Location
- USA
- Website
- www.pbase.com
- Can others edit my Photos
- Photos OK to edit
The AF-ON button is relatively "new" to Canon consumer d-slr bodies; earlier bodies in the xxD series, like the 10D and 20D had no AF-On button, but instead used the * button and a custom function setting in the menus to assign what Canon calls "back button focus"; in the consumer bodies, Canon introduced a dedicated labeled "AF-ON" button with the 30D or was it the 40D???
Nikon bodies vary in their controls; the "pro" body D1 and D2 series bodies had two buttons AF-ON and AE-AF lock located side by side, with a number of different functions possible to assign. On the D3 series, those two buttons have been re-located.
There are plusses and minuses to both systems; sometimes it's easier and better to separate the focusing acquisition from the shutter release action, while other times there's very little advantage. In long-lens, spot-focus work like baseball or high jump events where the peak of action will occur at a SPECIFIC location, it's often better to have the AF located on a thumb control, so you press the AF ON button with your thumb to activate the AF, get an AF lock, and then wait with the camera aimed at the target area on a monopod as the action approaches the exact spot where the AF has already been set to--like a slide into second base, or a throw to first base, or the high jumper as he clears the bar...
Nikon bodies vary in their controls; the "pro" body D1 and D2 series bodies had two buttons AF-ON and AE-AF lock located side by side, with a number of different functions possible to assign. On the D3 series, those two buttons have been re-located.
There are plusses and minuses to both systems; sometimes it's easier and better to separate the focusing acquisition from the shutter release action, while other times there's very little advantage. In long-lens, spot-focus work like baseball or high jump events where the peak of action will occur at a SPECIFIC location, it's often better to have the AF located on a thumb control, so you press the AF ON button with your thumb to activate the AF, get an AF lock, and then wait with the camera aimed at the target area on a monopod as the action approaches the exact spot where the AF has already been set to--like a slide into second base, or a throw to first base, or the high jumper as he clears the bar...