topic Re: EF100-400mm L IS II USM suddenly stopped focussing in EF & RF Lenses

EF100-400mm L IS II USM suddenly stopped focussing

MikeMazet — Tue, 12 Sep 2023 08:11:59 GMT

I replaced my EF100-400mm first series lens with 2nd series a couple of years ago. I noticed over the last few weeks that focussing had become problematic with the lens failing to focus on the occasional subject (mostly birds among thickets of tangled branches). This seemed intermittent and I was hoping it was the branches that were causing the issue. But, suddenly, overnight the lens stopped focussing altogether, and that's when pointing at clearly defined, uncluttered subjects. I am an experienced photographer and know this isn't down to wrong settings etc. But what can be the cause? Are the motors on these lenses likely to fail after 2 years? The motor still drives the focussing but not every time, and it never achieves focus. After a couple of whirrs it gives up. If it's the motor, is it worth replacing? Anyone know the cost? (I'm in France, so a € price would help.)

Re: EF100-400mm L IS II USM suddenly stopped focussing

Waddizzle — Tue, 12 Sep 2023 10:32:14 GMT

Welcome to the forums! Sorry you are experiencing issues with your gear.

I would like to ask a few basic questions to get a better understanding of your issue so that I can form a baseline on how to troubleshoot your issue. Seeing how you are a highly experienced photographer, please do not be offended by the simplistic nature of some of the questions that myself or others might ask. Thank-you, for your understanding and cooperation.

What camera body are you using with the lens? Did you purchase a new lens from Canon or a Factory Authorized Dealer? Was it used?

Do you have any filters installed? If so, remove them. This lens and UV,CPL filters do not seem to agree with one another. I think it has something to do with the internal lens coatings.

Re: EF100-400mm L IS II USM suddenly stopped focussing

Anonymous — Tue, 12 Sep 2023 13:26:08 GMT

Have you tried removing and reinstalling the lens to wipe the lens and camera contacts? Do you have another camera to try the lens on? Do other lenses work ok with your camera? Trying these suggestions will help narrow down the cause of your focusing issue.

Re: EF100-400mm L IS II USM suddenly stopped focussing

MikeMazet — Tue, 12 Sep 2023 14:05:38 GMT

Thanks Bob. Yes, I have tried all the obvious solutions. Other lenses work on my 7D body but the 100-400 lens does not work on my 5D body or 7D. I have carefully wiped the connections on lens and body. They look pristine so I assume this isn't the problem.

Re: EF100-400mm L IS II USM suddenly stopped focussing

Anonymous — Tue, 12 Sep 2023 14:28:11 GMT

There is a firmware update for that lens, v1.07. It was to solve IS problems, but no mention of focusing problems. Just one other question, is the lens mount loose on the lens? As Waddizzle mentioned, some have reported issues with that lens and some filters. Do you have a filter on the lens?

Other than that, it would seem it needs to be sent to Canon for repair.

Re: EF100-400mm L IS II USM suddenly stopped focussing

MikeMazet — Tue, 12 Sep 2023 14:41:22 GMT

Hi Waddizzle.

The lens was purchased new, more than 2 years ago so out of warranty. It is well looked after and has suffered no bumps or falls that I know of.

I have 5D MkII and 7D MkII bodies and the 100-400 no longer works with either body. It is usually left mounted on the 7D.

I tried removing the UV filter but this has made no difference.

I can achieve perfect focusing on the manual setting, so everything internally appears to be still aligned.

Hope this helps.

Mike

Re: EF100-400mm L IS II USM suddenly stopped focussing

Waddizzle — Tue, 12 Sep 2023 14:48:01 GMT

“ I have 5D MkII and 7D MkII bodies and the 100-400 no longer works with either body. It is usually left mounted on the 7D. “

Well that pretty much sums it up right there alone. There seems to be an issue with the lens. It needs to be sent in for an inspection and a likely repair.

Re: EF100-400mm L IS II USM suddenly stopped focussing

MikeMazet — Tue, 12 Sep 2023 14:52:00 GMT

The lens attaches to the body very firmly. Removing the UV filter makes no difference.

Any idea as to the range of possible problems that Canon would be looking for? Does recalibration resolve issues like this or am I probably looking at a new motor? Any idea of costs? My 2x bodies are old and will need to be replaced at some point and I had considered mirrorless, so I'm reluctant to spend a fortune repairing a lens that may become obsolete, although at just over 2 years old it should have a long life ahead of it! My Series 1 100-400mm was still going strong when I changed it after nearly 20 years (and now my son-in-law uses it).

Re: EF100-400mm L IS II USM suddenly stopped focussing

Anonymous — Tue, 12 Sep 2023 15:10:05 GMT

I just thought of something else to check, is the focus limiting switch in the correct position? I would try moving that switch and the AF/MF switch back and forth a few times to make sure that they are making contact. If that fails, I would suggest contacting Canon repair and getting an estimate. If you get it repaired and later get a mirrorless R series camera, you can use a Canon adaptor and continue to use the lens. I use that lens on DSLRs and I would get it repaired if it were mine. It is a fantastic lens.

Canon Repair Web Site

Re: EF100-400mm L IS II USM suddenly stopped focussing

MikeMazet — Tue, 12 Sep 2023 15:24:47 GMT

Thanks again. I have moved the lens button back and forth from AF to MF, and the other from full to 3m-infinity with no effect.

When I take up the camera and depress the shutter button, it makes a one-off effort to focus but quickly gives up, always stopping at one end or other of the focussing range (0.98 or infinity). It won't try to focus again until it has been left to rest for a few minutes or turned off and on again when it repeats this cycle. I don't know if that might be a further clue as to where the problem lies.

Mike

Re: EF100-400mm L IS II USM suddenly stopped focussing

Anonymous — Tue, 12 Sep 2023 15:31:41 GMT

In the camera's AF menu, look for setting of Lens drive when AF impossible and make sure it is set to ON.

Re: EF100-400mm L IS II USM suddenly stopped focussing

Waddizzle — Tue, 12 Sep 2023 15:48:33 GMT

BTW, if you switch it to Intelligent Auto Mode, Green[A+] mode, and it still does not want to focus on either body then there is definitely an issue with the lens.

Re: EF100-400mm L IS II USM suddenly stopped focussing

ebiggs1 — Tue, 12 Sep 2023 15:52:10 GMT

" It needs to be sent in for an inspection and a likely repair."

Not so fast Mike, yes, I agree, yes, it is probably the lens and, yes, it is worth servicing. However lets do a simple test first. You have found out that cleaning the contacts never, I used to say rarely but never seems a more appropriate word, helps. But a full reset of either or both of your fine cameras just might. Do a Clear all settings and Clear all custom settings. The latter is very important so don't pass it by.

Now set either one to P mode. One shot never Ai-servo and make positive the lens switch is in AF. ISO 200 and daylight. Now on a bight sunny day go outside and try to shoot various subjects. Make sure they are high contrast and have vertical lines in them. Like a fence or buildings, light poles anything just varied subjects. If it doesn't work you can be pretty assured it is faulty and needs service.

Mike anything made by the hand of man can and will eventually fail. Some sooner than others and some sooner than they should. Canon may not be the cheapest repair but they will go through the entire lens and make sure it is up to spec. And you will get a warranty of their work and parts.

Re: EF100-400mm L IS II USM suddenly stopped focussing

MikeMazet — Tue, 12 Sep 2023 20:29:38 GMT

Thanks EB. I’ll try your suggestions in day light tomorrow.

Re: EF100-400mm L IS II USM suddenly stopped focussing

Waddizzle — Tue, 12 Sep 2023 21:25:11 GMT

@MikeMazet wrote:
Thanks EB. I’ll try your suggestions in day light tomorrow.

Testing the lens in Green[A+] mode has the net result as resetting the camera. If the lens does not focus, then it needs to be checked out and probably repaired.

Re: EF100-400mm L IS II USM suddenly stopped focussing

Anonymous — Wed, 13 Sep 2023 01:17:40 GMT

Have you checked the setting in the AF menu for the setting of Lens drive when AF impossible and make sure it is set to ON. This sometimes helps when a long zoom lens has issues focusing.

Re: EF100-400mm L IS II USM suddenly stopped focussing

MikeMazet — Wed, 13 Sep 2023 07:20:34 GMT

Not sure what Green(A+) mode means but if it is a camera setting maybe it's not available on MkII models of 5D & 7D. Yes, I did check the 'lens drive when AF impossible' setting, but same negative result. And tried EB's suggestions of full camera reset, P @ 200ISO, sunny morning here, sharp high contrast lines of rooftops/walls. Lens still won't focus. No option left but to give the lens to Canon. Great community, guys! Thanks for all your help...

Re: EF100-400mm L IS II USM suddenly stopped focussing

Waddizzle — Wed, 13 Sep 2023 13:17:42 GMT

Green [A+] mode? Look at the shooting mode dial on top of the camera.

[EDIT] Let us know how you make it with the lens repair.

Re: EF100-400mm L IS II USM suddenly stopped focussing

MikeMazet — Wed, 13 Sep 2023 13:18:34 GMT

Oh that! I've never used it before, but still can't achieve focus...

Re: EF100-400mm L IS II USM suddenly stopped focussing

ebiggs1 — Wed, 13 Sep 2023 14:40:18 GMT

"Testing the lens in Green[A+] mode has the net result as resetting the camera."

I don't like the "Green Square" always telling people with this level of camera to forget it even exists. If you want a P&S buy a PowerShot. But if you are going to buy a semi-pro camera you should be beyond the Green Square! Besides I prefer to have the camera set back to a completely known zero in every respect.

Sorry it didn't work but now you know for sure. Call Canon 1 (800) 652-2666