topic Re: EOS 90D autofocus keeps switching from AI to M in EOS DSLR & Mirrorless Cameras

EOS 90D autofocus keeps switching from AI to M

Birder_Girl4 — Thu, 26 Sep 2024 19:09:28 GMT

I've been using the EOS 90D for three years with no issues. I use AI focusing mode as it best meets my needs for bird and wildlife photography. Recently the focus mode has begun jumping from AI to M with just the slightest move of the camera. I set it to AI and as soon as I press the shutter it jumps back to M. This has been happening with every lens I've tried and with various exposure settings. The battery is new and fully charged, and all camera and lens settings are at AF. Any idea what is causing this?

Additional info re: earlier post about 90D autofocus problem

Birder_Girl4 — Fri, 27 Sep 2024 14:48:54 GMT

I originally posted about a problem with my 90D switching from AI focusing to M focusing. Here is more information to clarify the problem. I am a bird and wildlife photographer and use AI Servo for my photography. Recently the focusing mode has begun switching to MF manual mode despite the fact that my camera and lenses are set to AF auto focus. This happens regardless of which focusing mode (AI Servo, AI Focus, or One Shot) I try. It also happens with each shooting mode I try. This morning when I tried to shoot in AI Servo it immediately defaulted to MF manual focus. I am now unable to get it out of MF, it appears to be stuck in that mode. I did try to manually focus an image but when I pressed the shutter nothing happened. The problem began over a month ago but has gotten increasingly worse making it nearly impossible to use the camera. I have no idea why this is happening and any help would be greatly appreciated Is it time to ship the camera off to Canon for repairs?

Thanks for any advice you can give.

_Birder_Girl4

Re: EOS 90D autofocus keeps switching from AI to M

deebatman316 — Fri, 27 Sep 2024 15:01:04 GMT

What lens are you using please provide the FULL NAME of the lens in question. Not just for instance "EF-S 18-55mm" there are many variants of that lens. So the specific name is very important.

Re: EOS 90D autofocus keeps switching from AI to M

Birder_Girl4 — Fri, 27 Sep 2024 15:12:18 GMT

Thanks for your reply. I use the Tamron SP 150-600mm F/5-6.3 Di VC USD AO11 and the Canon EF 100-400 mm f4.5-5.6L IS USM.

I've been using both of these lenses with the 90D for three years with no issues until recently

Birder_Girl 4

Re: EOS 90D autofocus keeps switching from AI to M

deebatman316 — Fri, 27 Sep 2024 15:17:59 GMT

I want to confirm the EF lens is this the original EF 100-400mm lens with the push pull zoom. Or the newer one with a dedicated zoom ring. I would try retesting both lenses on a different camera to see if both lenses are doing the same thing. Also the EF 100-400mm lens has mechanical focus override while in AF mode. You don't need to half press the shutter button to allow focus override to work. This lens doesn't have an electronic focus ring like STM, Nano USM and some early Ring Type USM lenses do.

Re: EOS 90D autofocus keeps switching from AI to M

Birder_Girl4 — Fri, 27 Sep 2024 15:25:39 GMT

The EF100-400mm lens is the original with the push pull zoom. The Tamron 150-600mm lens is 1st generation. Both of these lenses work perfectly on my old 7D (first generation, not 7DII).

Re: EOS 90D autofocus keeps switching from AI to M

deebatman316 — Fri, 27 Sep 2024 15:33:42 GMT

Do you have another lens to test out on the 90D to see if it still happens.

Re: EOS 90D autofocus keeps switching from AI to M

Birder_Girl4 — Fri, 27 Sep 2024 16:05:23 GMT

I tried the EF 70-200mm 1:4L IS USM and the EF 70-300mm 1:4-5.6 IS USM. The same problem occurred with both lenses on the 90D. When I tried the 70-300mm lens "Error Message 3 Communication between camera and lens is faulty" appeared.

Re: EOS 90D autofocus keeps switching from AI to M

deebatman316 — Fri, 27 Sep 2024 16:09:16 GMT

What Canon has listed for error 3 doesn't match what you have. Link to Canon USA This sounds like an issue with the body.

Re: EOS 90D autofocus keeps switching from AI to M

Birder_Girl4 — Fri, 27 Sep 2024 16:10:17 GMT

I think this should read Error Code 30, not Error Code 3. It says communication between camera and lens is faulty.

Re: EOS 90D autofocus keeps switching from AI to M

deebatman316 — Fri, 27 Sep 2024 16:11:51 GMT

All of your lenses work on a different camera you mentioned but not the EOS 90D.

Re: EOS 90D autofocus keeps switching from AI to M

Birder_Girl4 — Fri, 27 Sep 2024 16:15:35 GMT

Sorry, I just checked, and it is Error 01.

Re: EOS 90D autofocus keeps switching from AI to M

deebatman316 — Fri, 27 Sep 2024 16:19:56 GMT

Is this on the 90D? What I would do is retest every lens and set the aperture to something small like F/8. Smaller than the maximum apertures of all lenses. Since these are all variable aperture lenses. Then press the depth of field preview button. This will make the aperture stop down. Canon focuses wide open until the exposure is made. The test can easily be done with the camera set to Av Mode.

Re: EOS 90D autofocus keeps switching from AI to M

Birder_Girl4 — Fri, 27 Sep 2024 16:41:15 GMT

Yes, this was on the 90D. I just tried your latest suggestion with each of the above-mentioned lenses, switched to AV mode and tried to set the aperture, but in each case I got a message "Cannot adjust Aperture because no lens is attached." I'm beginning to think that my 90D is dead, or is there still some hope for a fix?

Re: EOS 90D autofocus keeps switching from AI to M

deebatman316 — Fri, 27 Sep 2024 16:44:33 GMT

Does the camera report F/-- or F/00 in the viewfinder, top LCD screen and rear LCD screen. Or does it show an actual F/ Stop value such as F/5.6 for instance.

Re: EOS 90D autofocus keeps switching from AI to M

Birder_Girl4 — Fri, 27 Sep 2024 16:49:40 GMT

F00

Re: EOS 90D autofocus keeps switching from AI to M

deebatman316 — Fri, 27 Sep 2024 16:51:30 GMT

Are all of these lenses working with your EOS 7D classic. If they are the problem has to be with the camera body.

Re: EOS 90D autofocus keeps switching from AI to M

Birder_Girl4 — Fri, 27 Sep 2024 18:14:49 GMT

Thank you for your suggestions. I contacted a local repair shop, if they can't repair the 90D they will ship it to Canon for me.

Re: EOS 90D autofocus keeps switching from AI to M

408_Birding — Fri, 13 Feb 2026 03:17:42 GMT

Hi I just experienced the same issue with my setup today. They are almost identical to yours.

Canon 90D + Canon 100-400mm 4.5-5.6 ISII USM

I was using back-button AF to focus in on a subject and viewing through the viewfinder when the scene started jumping around. Often with a loud "clunk" sound.

I took it to a local camera shop to have them test both the body and lens and the lens seemed to work fine when paired with other bodies they used. So it seems like my issue is the same as yours - with the 90D itself.

I also got this error:
Err 01 - Communications between the camera and lens is faulty. Clean the lens contacts.

I cleaned the gold sensors on the lens with a dry cloth but no dice.

Wondering what you found out from Canon or your repair shop and hope to hear how it was fixed!

Thanks