Err 01 with the 50mm 1.4 on 6D

Having used the 50mm on the 6D a few times now without a hitch I switched back to use the lens again earlier on, and now see the Err 01

If I pop the lens on the 7D body all is fine, I can shoot without a problem. All other lenses work fine too

So I've given the contacts on the lens, and camera body a wipe to no avail. What would you suggest the next step was? Should I look inside the lens at the other end of the contact points?

With the 6D powered off, mount the lens and verify it fully rotates in the bayonet mount to the lock position. The lens mount/dismount button should pop out at the proper position.

Cheers John, just tried that a few time, and cleaned the contacts again but to no avail

The lens focuses as normal and takes the shot, but once the shutter closes the Err screen appears and no photo is saved.

Knock the 6D into Video mode and the lens makes a noise like a chirp/grinding I can take a photo with it like this but the shot has a blue line top and bottom of the image

How about trying/borrowing other lenses on the 6D??

I have Lee, they are all fine

More bizarrely, I can shoot at f1.4 just fine, anything else see's the Err code

I'm starting to suspect the AF drive system is at fault here and needs replacing.

So are you saying the lens works OK on the 6D so long as you manually set it at f/1.4? And to clarify "all is fine" on the 7D means it works on all f-stops?

After further testing:

The lens does work ok at f1.4 on both cameras, but not at any other F stop

I was sure I'd tried this before, but either way today that's how it is. Time to pack it off to a repair shop and await a bill - gutting as I've only had it a month, bought used

Having this exact problem. So disappointing.
Also, not behaving on my C100.

The guide for the focus inside this lens is very subject to bending from the least little bump. It is an easy repair for someone who knows lenses, but sad to say it will probably happen again.

ksbal wrote in post #18778478
The guide for the focus inside this lens is very subject to bending from the least little bump. It is an easy repair for someone who knows lenses, but sad to say it will probably happen again.

The thread is about the iris issue, not focus.