5Dmk II - AF issues..

[Chris G]

As the title states and I have little knowledge about this camera I'm turning to the Canon users here on the forum to perhaps maybe help me in finding a solution or cause as
to why a 5DmkII seems to lose focus on and off or wont at all.

This is for a friend of mind so I've already asked some of the basic stuff like 'Check connectors on lens and cam, AF points, not using manual AF, single AF ect ect..

So apart from the obvious settings we tend to check, what else could it be?

Cheers for any enlightenment

[ameerat42]

Did friend give any instances of when this would happen?
Am.

[Chris G]

errr actually no..

Though it was mentioned that it's happening on the Canon 24-70mm, does this happening with another lens? well thats a good guess at this stage as she's out and about.. lol

[ameerat42]

Well that's a place to start. If only on one lens then it isolates the problem some.
Am

[fess67]

I had a similar issue and tracked it down to the lens. In my case it was my 50mm 1.4 lens. Would work fine for a while and then refuse to AF at all. Then the next time I used it, no problems again. managed to duplicate the issue on my 50D as well. I did some reseach at the time and it was not an uncommon issue with my lens. May be worth hunting for any problems with the 24-70.

Other than that experience the AF on the 5D2 has been faultless.

[Bennymiata]

Which focus setting is he using?
If he's not on "One Shot", the focus may be drifitng because of moving objects, or perhaps he is using auto focus point, in which case, the camera could be using any one of 9 different points, or trying to focus on all of them.

[fabian628]

if the lens has focus limit switch could check that its not on. also could check the custom function which stops it hunting if focus is not acheieved. other than that, would not know anything.

[swifty]

Just speculating and not specific to any camera/lens combo.
But if it's with just one lens, check if the lens contacts are clean.
If its with all lenses, check the camera contacts.