Trouble with autufocus

becks12

For the second time in less than a week I can't seem to take photos on autufocus, nor on any of the guide options.
The shutter release will not go all the way down to take the shot. I can only shoot when the letter 'm' on the lens is chosen.
What am I doing to make this happen and how can I fix it?
Just landed in Africa and I'm desperate to get this sorted out!

JLG

How is your battery? I never use autofocus, so I have never had this happen to me. Does your lens have a little manual/autofocus switch on it? Is it switched all the way?

bruto

Make sure that the autofocus point is set correctly. It's very easy to accidentally move it, and then if you're using a single point auto focus mode, it will be trying to focus on the sky instead of your subject. Use the [OK] button to center it.

Make sure too that the lens is fully engaged. Remove it and put it back on once or twice to re-establish contact.

As an experiment try switching to Live View, and see if the lens autofocuses then. Live View uses a completely different system in the camera. If you get reliable AF with Live View, but not with viewfinder view, the fault may be in the camera's AF system. If neither works, the the fault is more likely in the lens.

This camera is set to "focus priority" mode, which means that if, for some reason, it cannot establish auto focus it will not shoot. Switching to manual focus removes that impediment, so if for some reason your AF is not working correctly, it's always an option.

Live View autofocus will be quite accurate, but not as fast, and not as able to track moving objects.

awdiver

I am having the same issue when in auto mode. Pictures are not completely sharp.

bruto

Auto mode uses only Auto Area focus, and that is not always accurate. Auto Area focus will tend to look for the nearest thing in the view that it thinks should be a subject, and focus on that. If you want more control over focus, you must get out of Auto mode.

To test that the AF is working correctly, try switching to P mode (exposure control will still occur), and set the AF to single point, single servo focus. Make sure then that the focus point is centered, by pushing the [OK] button. Now aim at an object and shoot a picture. Is it in focus? If so, then it's the AF mode that's at fault.