Canon 500mm f4 possible focus problem

I have owned this lens since new for 6 years. I have taken at least 200,000 images with it and until recently have been quite happy with it.

Beginning in March I began to notice auto focusing issues, at first with birds in flight and now with perched birds. For every 100 photos I'm finding only one or two are acceptable, the remainder are soft or blurry. In all cases the lens is being used outside in temperatures ranging from minus 5 celsius to about +3 celsius.

I have cleaned the contacts, ensured the camera is correctly set up, checked and rechecked the switches on the lens for AF and image stabilization, calibrated the micro focus and have ensured the lens elements are clean.

I don't have similar problems with my other lenses which include a 100-400mm vii and a 24-105mm lens.

I'm beginning to ponder the idea that given the number of activations this lens has seen that it might be possible that the various internal mechanisms such as auto focus and IS are beginning to wear out.

Has anyone else experienced or heard of this? Should I send the thing into Canon for examination?

Any advice is appreciated,

Thank you,

Herman

Have you tried AFMA. From what you have said I expect that micro-adjust should solve the problem. It is definitely worth a try.

You don't say if this is a Mk I or Mk II lens or whether you are hand-holding it, or using it on a tripod. You don't say which camera body you are using - some Canon camera bodies have had problems with the mirror box and that would account for the results you are reporting.

I would try using it on another body and see if the results are the same. I think Canon no longer service Mk I lenses, so you might have to look for an independent repairer, if that is required.

Lots of possibilities, but first determine if the lens is capable of taking a well focused shot. Start by shooting something inside your home using Live View on a tripod. This is a baseline shot. Next, defocus it manually, and refocus through the viewfinder (normal shooting). If the LiveView shot looks better, you need AF fine tuning. If they are the same, and good, you have a different issue. If they are both bad you likely have a lens/camera issue.

Start there and let us know what the results are.

If your lens is serviceable by Canon (i.e., version 2), I suggest you determine whether it is beneficial to become a Canon CPS member before sending it into Canon for repair, so that you can get the Canon discount on the repair job. I suspect repairs on the super-telephoto lens could be expensive. Best wishes for a successful outcome!

Yes, I have done the micro adjust and found that no adjustments were required. The best images were at zero on the focus test chart.

Phil Shaw said:

You don't say if this is a Mk I or Mk II lens or whether you are hand-holding it, or using it on a tripod. You don't say which camera body you are using - some Canon camera bodies have had problems with the mirror box and that would account for the results you are reporting.

I would try using it on another body and see if the results are the same. I think Canon no longer service Mk I lenses, so you might have to look for an independent repairer, if that is required.

Click to expand...

It's a mark one lens mounted to a Canon 7d mark 2 camera. All shots were taken from a tripod, with birds in flight stabilization was set to 2, with perched birds set to 1. Shutter speeds were a minimum of 1/1250 sec.

I will try it on my Canon 7D and see if there is a difference. The 7D mark 2 now has 98,500 shutter actuations on it, the 7D likely has as many.

Herman

Hopefully it is an issue with your 7d mk2 or there is someone who can work on your lens with the necessary parts needed where you live. In the US Canon will no longer service the 500mm f/4L IS USM which is a real bummer.

I had a 100-400mm L that had symptoms just like you describe. In my case I was able to use the AFMA to get sharp photos until eventually it needed so much that it needed to be sent in to Canon for service. When that happened Canon replaced the mounting flange and contacts and everything was fine. If you use live view for AF do the pictures consistently come out sharp?

I am currently experiencing the same issue as you did with the same lens (500mm F4).

Did you get it resolved?

Mako Photo said:

I am currently experiencing the same issue as you did with the same lens (500mm F4).

Did you get it resolved?

Click to expand...

I had a problem some years ago with my copy of the original EF 300 F/2.8L. I suspect that I'd damaged the lens by trundling it, in its padded case, in a "granny" shopping trolley over rough pavements and similar. Since then I've always carried my big whites on my back.

I had difficulty getting it repaired, but eventually I had success having it done by one of Canon's 3rd. party independent UK repairers - and I wasn't charged for any spare parts.