topic Re: EF 70-200 2.8 IS USM: does not focus in EF & RF Lenses

EF 70-200 2.8 IS USM: does not focus

NancyEv — Tue, 06 Feb 2024 16:28:31 GMT

Recently, I am unable to focus my lens using the focus ring (stuck on infinity-when I turn the ring, nothing happens (R7 camera). When I try to use center point focus, the camera cannot focus on things closer than infinity. Sometimes Eye-detect works, but most of the time it doesn’t. Also, when I shoot in eye-detect mode, the first picture is sometimes good, but subsequent images lose focus. Thoughts?

Re: EF 70-200 2.8 IS USM: does not focus

Tronhard — Tue, 06 Feb 2024 17:16:28 GMT

Hi Nancy and welcome to the forum:
Sorry to learn you are having issues. To try to eliminate possibilities, let's explore some variables.
What brand of adapter are you using to connect your lens to your R7, please?
Are you able to test the lens on a DSLR body?

Re: EF 70-200 2.8 IS USM: does not focus

NancyEv — Tue, 06 Feb 2024 17:36:09 GMT

A canon adapter. I no longer have a DSLR. This behavior of the focus ring not moving off infinity occurs when the lens is off the camera. I’ve used this lens successfully for many years; I don’t think this is operator error :). I can’t find anything about this in the manual, and have searched around the support site, but can look some more.

Re: EF 70-200 2.8 IS USM: does not focus

Tronhard — Tue, 06 Feb 2024 17:41:38 GMT

Hi again:
Thanks for your prompt response. No suggestion of operator error from me. However, I still need to isolate the cause.
Just to clarify: I'm not sure what you mean by "This behavior of the focus ring not moving off infinity occurs when the lens is off the camera." I am trying to reconcile this with your other statement "When I try to use center point focus, the camera cannot focus on things closer than infinity"
Did the lens ever work at all when using the EF-RF adapter?

Re: EF 70-200 2.8 IS USM: does not focus

NancyEv — Tue, 06 Feb 2024 19:18:06 GMT

Okay, I’ve done some more testing.
—When I put the lens on the camera (R7 with a canon adapter), I can focus, and the little window showing the distance on the lens changes to something approaching the real distance. This didn’t seem to happen all the time in the field last week.

—When I put the lens in MF mode, the little window says infinity no matter how much I turn the focus ring, and I can’t manually focus on anything, close or far.

—Interestingly enough, when I push the shutter button, the view through the viewfinder seems to jump to in focus only while I have the shutter depressed, even when the lens is in MF mode. I have dissociated focus from my shutter button so this was a surprise. I double checked my settings and I do not have any focus on my shutter button.

—I’ve been going through my photos from a recent trip and have a surprising number where the first photo in a series is sharp, and subsequent ones go out of focus slightly (subject did not move), which is not my experience with my 500mm lens.

Re: EF 70-200 2.8 IS USM: does not focus

Tronhard — Tue, 06 Feb 2024 19:25:09 GMT

Hmmm... thanks for that info.
Well, my first thought is to look at the configuration of the R7. Can you please check to see if you have the latest firmware updates for your camera? If not, I would suggest doing the update and retesting.
The other thing I would suggest is, after saving your current configuration to one of the C modes, is to do a camera reset and check to see how it is then performing.

Re: EF 70-200 2.8 IS USM: does not focus

deebatman316 — Wed, 07 Feb 2024 02:46:26 GMT

Have you tried turning the focus ring both ways to see if it moves away from infinity. This lens supports what Canon calls Full-time Manual Focus. The focus ring can be turned with the lens set to AF. Without any type of damage because there is a clutch underneath the focus ring. If it does move from infinity there's nothing wrong with the lens. Also which EF 70-200mm F/2.8L IS lens do you have. Canon has released 3 different versions over the years.

Re: EF 70-200 2.8 IS USM: does not focus

ebiggs1 — Wed, 07 Feb 2024 15:33:17 GMT

I would do the reset and clear all custom settings too. I would not save your current settings because if that is the issue why would you want them back. I also doubt a FW update will accomplish any improvement unless it specifically mentions your specific lens.

Sorry to say but this may be user error.

Re: EF 70-200 2.8 IS USM: does not focus

NancyEv — Wed, 07 Feb 2024 16:20:34 GMT

Hi--It is a EF 70-200mm f/2.8L IS USM according to the label on the lens (but according to Canon, the serial number belongs to a IS II USM...go figure). When I turn the focus ring in either direction, the focus window doesn't change whether the lens is on or off the camera. BUT--today when I was testing to confirm, the focus window switched to ~5m and then back to infinity (right after I put it on the camera).

Re: EF 70-200 2.8 IS USM: does not focus

NancyEv — Wed, 07 Feb 2024 16:22:01 GMT

I have updated the firmware to 1.4.0. I will do a camera reset today. I think I'll take it all the way back to factory settings just to be complete. I will post with the results.

Re: EF 70-200 2.8 IS USM: does not focus

deebatman316 — Wed, 07 Feb 2024 16:22:34 GMT

Do you hear the AF motor running all the time.

Re: EF 70-200 2.8 IS USM: does not focus

NancyEv — Wed, 07 Feb 2024 16:24:42 GMT

Will do today...I agree that some of the behavior may be user error (or lens error compounded by user error), but I've been using this lens forever and the lack of being able to focus manually seems outside of the realm of an error on my part.

Re: EF 70-200 2.8 IS USM: does not focus

NancyEv — Wed, 07 Feb 2024 16:46:26 GMT

Yes, whether in MF or AF, and with or without IS on.

Re: EF 70-200 2.8 IS USM: does not focus

deebatman316 — Wed, 07 Feb 2024 16:49:35 GMT

Remove the lens from the camera then turn the focus ring. The AF motor should not be active when the camera is off.

Re: EF 70-200 2.8 IS USM: does not focus

NancyEv — Wed, 07 Feb 2024 17:11:49 GMT

When I turn the focus ring when the lens is off the camera, nothing happens in the focus window.

Re: EF 70-200 2.8 IS USM: does not focus

deebatman316 — Wed, 07 Feb 2024 17:16:06 GMT

Even if you turn it both ways? Do you feel any resistance when turning it. The focus ring should turn indefinitely. You'll feel resistance at the end of the focus through. But it will keep turning.

Re: EF 70-200 2.8 IS USM: does not focus

NancyEv — Wed, 07 Feb 2024 17:36:33 GMT

Slight resistance when turning either way and no change in resistance even when turning the ring 3-5x around.

Re: EF 70-200 2.8 IS USM: does not focus

deebatman316 — Wed, 07 Feb 2024 17:39:40 GMT

There should be a part where it turns smoothly without resistance. Until you get to the end of the focus throw. The focus ring will turn 360 degrees. But there is a clutch underneath the focus ring. It sounds as if your lens is broken.