I have a newish to me 5D2 (with a return policy) and a 24-105 lens. I have had the lens for a while, no issues previously. On two occasions, I have been shooting and have gone to focus and shoot, and on pressing the focus button (AF-ON for my setup) it seems like the auto-aperture hangs, the camera confirms focus even though it's not focusing. By auto-aperture hangs, I mean that it seems like the aperture is stopped down when it should not be (the view through the viewfinder becomes darker, like using a MF lens). So I think either the lens blades are sticking or the camera is giving it an incorrect signal.
At this point, I am not sure if it's a camera issue or an issue with my lens. I guess I can mount up the lens on the T3i and see if I can repro the issue.
Otherwise - has anyone seen this before, and any idea as to whether it's a lens or camera body issue? If I need to send the body back, I have to do it tomorrow (I had a 7 day return window which ends Monday) so I need to make a decision about it today.
This is further compounded by me picking up a refurb 5D2 on sale yesterday, so I was planning to sell the 5D2 that I have now anyway, but I feel like if I suspect there is something wrong with it, it needs a trip to Canon. So perhaps that's another reason to return it to the seller and let them sort out what to do with it?