autofocus with wide angle (Tokina 10-17) zoom or manual focus ?

[jan10]

With my Tokina 10-17mm I have to choose between AF (and then I can zoom - 10 <-> 17 - with the zoomgear) or I set to MF, but then I can not focus from my housing anymore.
Sometimes I have the problem with big fish with AF that my camera has difficulties with focussing and I missed the opportunity !
So are some photographers in those cases setting the lens on MF and on a certain distance (how much ?) and hoping that the DOF is just enough to have a sharp picure ?

 

[alcina]

Sorry, can't help - I use mine in AF and haven't had it miss yet

 

[PatW]

I am assuming that you are using the Tokina 10-17 fisheye. A problem that one can have is that the autofocus is activated by a half pressed shutter button. My DSLR allows me to seperate the auto focus control to another button entirely (I think that most DSLRs MUST have this feature). The shutter button becomes dedicated to taking the shot only. So I can fool with my autofocus until I have it where I want it. Then I compose my shot and take the photo.

Now since the 10-17 is a very wide lens, even with a pretty low F stop, you still should have a wide depth of field. Even with a moderate F stop, like F 8, anything very near your plane of focus should be covered unless you are focusing at something that is very close.

 

[mjh]

Not familiar with Canon but stick with Auto Focus but you may want to set the Focus Mode on your camera to Single "Point" then you can choose the point the camera is using to grab focus.

 

[darook]

I use center point focus in one shot mode on my 550d. The center is the only cross type focus point on my camera and thus the most accurate. In one shot mode I just focus and recompose. Even wide open the 10-17 has a really deep DOF.