70-200 2.8 wont AF sometimes

I was using my 70-200 last night in some cold temperatures (20 F) And when I got home and tried to use it, it wouldn't AF. This has happened before, and when it has, I took the lens off, cleaned the contacts and put it back on, and it worked fine. Does anyone else have this problem.

Did condensation get in it? When going inside after freezing temperatures, one ought to put the lens(es) and body into plastic bags or the like to keep condensation from the equipment.

When moving the camera directly from extreme cold to a heated area, I place the camera and lens into a plastic bag first so that condensation is on the bag, not the gear.

The AF does work now, And this happened in the summer as well.

As for condensation, it went from a backpack to a cold car which gradually warmed up, so I think it should be fine. Right?

You'll have to try that lens on another body to see if it is the lens or your camera at fault.

Yes I have had a similar problem but I put it down to the cold weather, moving from very cold to very warm conditions. The lens soon recovers, I just make sure I bag it now when moving back to a warm environment.

Maybe you are under the MFD of the lens.

When I bought (used) 70-200mmf 2.8 non IS, I was worried as I had AF problems. Turned out MFD of the non IS is worse than the MFD of the IS version.

bobbyz wrote in post #6940271
Maybe you are under the MFD of the lens.

When I bought (used) 70-200mmf 2.8 non IS, I was worried as I had AF problems. Turned out MFD of the non IS is worse than the MFD of the IS version.

That is a big possibility, and would explain it all. When ever it didnt work, it was always with close subjects.

Thanks, Happy Holidays!