Originally posted by Pepe Guitarra My question is more information gathering (thirst of learning) than critic. Here is a re-word: How do you control the focus in a very wide angle, if you are using AF? It will tend to focus the center of the photo, or if you have focus point, then those focus points. What if ou just want to focus the foreground which could be framing the subject? If you can help me, go ahead and answer. Thanks, Pepe
Well I'd say except if you go for near macro/proxy, you have lof of deph of field with a WA. At 18mm on APSC, at f/2.8 and focussing 2meters away the deph of field is already more than 1meter.
In this kind of conditions you can focus with the center AF point and reframe. If you want to have all in focus, you can use hyperfocal distance...
17mm f/4, 4 meter is the hyperfocal distance with everything in focus from 2 meter to infinite. close down to f/8, hyperfocal is 2meters, and then if you focus on hyperfocal everything from 1meter to infinite will be in focus.
To use hyperfocal distance, just use the center AF point to focus to something that is at this distance approximately and you are done as long as you foreground is not outside the area of focus.