I'm thankful to find this forum!
I have had the original version of this EF 100-400mm f/4.5-5.6L IS USM lens for a while, used mostly for wildlife trips. My 70-200mm f/2.8L II has been living on my camera 🙂
I am completely obsessed with birds and wildlife (again). So, I excitedly unpacked this lens, mounted it on my 5D and went in search of critters.
Something is wrong. Hopefully it is something I am doing wrong and not a mechanical issue.
I am having issues with a glass element moving, shifting up to where I can see the bottom and then shifting back down. It is audible when it happens.
It happens throughout the zoom range, with the AF/MF selelctor in either position, IS on or off, in either IS mode and with any range selection.
I can get to a place with the focus I want, shutter release pushed halfway and when I push completely to take the photo the element shifts.
Sometimes if I hurry and try to get an AF shot, seemingly without giving the camera the time to think, I can get a picture without the element shifting.
This happens when mounted on both my 5D mkII and 7D, with no error messages from the cameras 😞
I haven't seen this issue before with any of my lenses, and I don't remember it happening before with this lens.
The IS system is broken. Where did you get the lens?
"I have had the original version of this EF 100-400mm f/4.5-5.6L IS USM lens for a while,..."
What is "for a while"?
I would return it immediately if possible. Don't send it to Canon since it should not be your job to fix it unless you were told it was faulty up front. If "for a while" means months or years, than of course it is on you. A used 1st version 100-400mm is $400 to $500, keep that in mind. But a significantly better model is out now. This might be the time to investigate buying a new lens. The Canon EF 100-400mm f/4.5-5.6L IS II USM Lens
Thank you so much for the information.
I have had it for about 5 years. My extended coverage was only for 3.
I will start saving for a new lens.
Contact Canon Support, anyway. Make them pity a dedicated Canon user, whose lens has died for no explicable reason.
"Make them pity a dedicated Canon user,..."
Yeah, you can try that but I would start the savings account for the new lens. That said if you like your lens it won't hurt to see how much to repair and exactly what is wrong with yours.
The new model is a very much better lens and worthy of the upgrade whether yours works or not.