topic Canon 70-200m F2.8 USM autofocus not working in EF & RF Lenses

Canon 70-200m F2.8 USM autofocus not working

iyamdman — Tue, 29 Aug 2017 15:53:48 GMT

I have an old (20 years old) 70-200mm F2.8 USM EF lens. I just bought a Canon 6D body, and the lens wont auto focus.

When I hold the shoot button half way, the lens is just focusing back and forth, and not finding anything to focus on.

My other old EF lens 14mm F2.8 EF lens works fine, but the 70-200mm F2.8 is having issues.

Is this a compatability issue between the lens and the body, or is this a lens issue?

Re: Canon 70-200m F2.8 USM autofocus not working

Waddizzle — Tue, 29 Aug 2017 23:52:24 GMT

@iyamdman wrote:
I have an old (20 years old) 70-200mm F2.8 USM EF lens. I just bought a Canon 6D body, and the lens wont auto focus.

When I hold the shoot button half way, the lens is just focusing back and forth, and not finding anything to focus on.

My other old EF lens 14mm F2.8 EF lens works fine, but the 70-200mm F2.8 is having issues.

Is this a compatability issue between the lens and the body, or is this a lens issue?

It sounds like it is most likely an issue with the lens. Make sure you're conforming to all of the rules about sufficient light, contrast, focusing distance, etc.

Trying out the lens on another camera body should confirm or deny your suspicions about the lens.

Re: Canon 70-200m F2.8 USM autofocus not working

ebiggs1 — Wed, 30 Aug 2017 15:05:30 GMT

"Is this a compatability issue ~~between the lens and the body,~~ ~~or is this a~~ lens issue?"

As far as I know any EF lens will work on any EOS camera. Never hurts to try it on another body though. My current oldest EF lens about 20 years old and still works fine.

Re: Canon 70-200m F2.8 USM autofocus not working

TCampbell — Wed, 30 Aug 2017 16:08:50 GMT

I'm not sure which exact model of the 70-200 f/2.8 you have (there are a few of them). I own the EF 70-200mm f/2.8L IS USM as well as the new EF 70-200mm f/2.8L IS USM II.

There is a range-selection switch on the side of the lens barrel that allows you to limit the focus range for subjects you know are far vs. subjects that might be close. For example on my lens the choices are 1.4m - ∞ vs 2.5 - ∞.

If your lens is on the 2.5m - ∞ setting but the subject is closer than this minimum distance, then the lens will struggle without successfully achieving focus.

If your subject is farther (say 10' or farther) and the lens cannot achieve focus, then contact Canon for service.

The lens should work with you camera body without issues. The only limitation you have for Canon EOS lenses is that you cannot use crop-frame (EF-S lenses) or mirrorless (EF-M) lenses on your full-frame camera body. But the 70-200 lenses are all "EF" (full-frame) lenses.

Re: Canon 70-200m F2.8 USM autofocus not working

Cj7509 — Sat, 19 Nov 2022 05:44:43 GMT

Hey, were you able to figure out what the issue was? I’m having the same problem right now.

Re: Canon 70-200m F2.8 USM autofocus not working

ebiggs1 — Sat, 19 Nov 2022 16:54:29 GMT

This is a 5 year old thread you should start a new one with you issue explained in detail so we can try and help.

Re: Canon 70-200m F2.8 USM autofocus not working

jrhoffman75 — Sat, 19 Nov 2022 17:49:19 GMT

@ebiggs1wrote:
This is a 5 year old thread you should start a new one with you issue explained in detail so we can try and help.

Yes, and identify the exact lens you have.

Re: Canon 70-200m F2.8 USM autofocus not working

Cj7509 — Sat, 19 Nov 2022 23:25:18 GMT

Sorry about that. I’ve gone ahead and created a new post and hopefully y’all will be able to help me out.

Re: Canon 70-200m F2.8 USM autofocus not working

shadowsports — Sun, 20 Nov 2022 15:27:31 GMT

Agree John. Let's put this one back to rest.

https://community.usa.canon.com/t5/EF-RF-Lenses/Canon-70-200m-F2-8LUSM-MK1-autofocus-not-working/td-p/394514