Quote Originally Posted by shutterdown View Post
What puzzles me is why I would need to send the body in, too, since when I bought this lens, it worked perfectly on my 5DII. I had tried an AFMA on it, previously, but it didn't give me satisfactory results, being a zoom lens. I wasn't sure which end I should do the adjustment, so I left it as is. But, that wasn't a negative, since the lens was quite sharp without any adjustment.

So, now, I've got a lens that isn't what it was when I bought it, and all I would like Canon to do, is bring it back up to the specs that existed when I bought it, originally.
The components inside the camera are very sensitive. If there off a bit they will send the wrong information to the lens. You could have bumped it or shaken it, or just general wear and tear changed things. If you compare the lens all the way through all of the settings then you can decide what is appropriate. There is nothing wrong with switching settings in the field if a subject is closer or further. Or you could do an average of the two ends. I prefer to set to the long end since the DOF is narrower there.

It my understanding that there is variance in the mfg process, notice the latest release of the 24-70 II. So it is best to send camera and body in that way Canon can make sure it matches manufactures specs in performance.