06-25-2020 04:41 AM
I own a 200/2.8 L II USM. Bought it used in 2008, in great condition. I've used it a lot over the years. Always carried in a well-padded bag, never dropped or handled roughly.
It worked normally as late as a few months ago, when I last used it before this week. Suddenly, it refuses to focus to infinity using autofocus. It gets nearly there, up to maybe 500 ft, but farther objects than that just won't get into focus. The shutter won't release (since I have focus priority over shutter release). However, if I manually nudge the focus ring the last bit, focus is achieved and the shutter will release. Manual focus works normally, at all ranges, so it's not an optical issue.
I've tested on two camera bodies, a 77D and a 90D, with exactly the same behavior on both. I've also tried both through-viewfinder AF and live view AF, and the problem is present and identical in both situations.
Yesterday, I was briefly able to get it working by flicking the focus limiting switch between the two positions (the 200/2.8 L II USM has a switch that limits the close end of the AF range to 3.5 m distance instead of the optical close focus distance of 1.5 m, but neither setting affects focus at infinity). I thought the problem was solved then, but the issue is back today.
It's obviously a problem with the lens itself, since all other lenses work fine, and the problem is present on two different camera bodies. And since I can manually focus to infinity, it's not an optical problem. Nothing is loose or visibly damaged. The golden contacts at the lens mount all look pristine, with no dirt or corrosion. The AF works normally at all distances shorter than about 500-800 ft. Fast, accurate and repeatable.
Any ideas? I really love this lens, so if this is an issue that can be fixed, I'd be thrilled.
06-25-2020 10:28 AM
It needs a C&C. "Bought it used in 2008, in great condition." However, you need to check if Canon does this any longer on early lenses. If not give Midwest Camera Repair a call but ask Canon first.
06-25-2020 10:31 AM
"Always carried in a well-padded bag, never dropped or handled roughly."
This statement is almost always the first thing people say when their gear breaks or needs service. These lenses are built to handle "rough".
06-25-2020 10:43 AM
Not sure what you mean by "C&C". I'm also around 4000 miles from Midwest Camera Repair...
I mainly want to find out what has gone wrong with it. Degraded capacitors? Misaligned AF sensor ring?
Since this happened so suddenly, without any impact or other damage (it sat on a table, untouched, between the last time it worked fine and now), I'm curious as to what could've happened.
A repair by Canon, if they even service 20+ year old lenses, would likely cost much more than the lens is worth (I paid the equivalent of around 500 USD for it in 2008, and I doubt it's worth even half of that today). I intend to fix it myself, if at all possible. If not, then I'll just consider it a manual lens from then on.
06-25-2020 10:46 AM
It may well be, but it's the truth. I don't travel, or go hiking or anything like that. My gear has only been used for walks about the city, and my lenses have either been in my padded backpack or on my camera, hanging in the strap around my neck.
06-25-2020 10:49 AM
"My gear has only been used for walks about the city, and my lenses have either been in my padded backpack or on my camera, hanging in the strap around my neck."
This is really not a consideration. This lens is designed to take it.
06-25-2020 10:51 AM
Ok, but either way irrelevant to my lens. It suddenly malfunctioned in this odd way while stationary on a table for 6-7 weeks.
06-25-2020 10:52 AM
"Not sure what you mean by "C&C". I'm also around 4000 miles from Midwest Camera Repair..."
C&C is clean and check. You are also 4000 miles away form me so I can not recommend any repair centers any closer.
"I intend to fix it myself, if at all possible."
06-25-2020 10:54 AM
Well, I'm not really looking for any repair center. I wanted to see if anyone here has experienced the same thing, and possibly also knows what the cause is.