I've been using my 7D ever since they first came out and I have never had an issue with it. It works great with my 70-200, 300mm f4, 400mm f5.6 and any other lens I have used it with. I recently purchased a Canon 500mm f4L IS version 1 and from day one I noticed a focus issue with the lens on my 7D.
I attempted to MFA and it needed -18 to get the focus to look right. This seems like a lot to me. What complicates this though is that the lens works absolutely perfectly on my 6D with no MFA required. Today I took it back to my friend that I bought it from and tried the lens on both of his 7D's and his 1D Mark IV. On both of his 7D's the results were the same, -18 MFA to get it right. But on the 1D Mark IV it was perfect at 0 MFA.
It is an older lens, the date code is from 2000 so I thought maybe the autofocus chip was having a compatibility problem on 7D's, but the fact that it works perfect on even newer cameras like my 6D and the 1D Mark IV has me really stumped.
I am a CPS member and I want to send the lens to them with the 7D, but I'm afraid that if they calibrate the combo to work well together that I will have issues when I put the lens on another body. I would like to use it with both my 7D and 6D.
I guess I could just live with the fact that it needs -18 MFA and just wait for the 7D Mark II or just get a 1D Mark IV, but for as much as I paid for this thing, I expect it to work perfect on whatever I put it on.
Any suggestions from anyone here who has experienced something like this before?
Here is a photo from yesterday after I got the MFA dialed in. This was from about 20ft shot wide open at F4 so I know I got it right. It just bothers me that it requires so much MFA to work. It's almost maxed out on MFA while other bodies need 0.