topic Re: RF 200-800 does not focus when starting at 800 mm in EF & RF Lenses

RF 200-800 does not focus when starting at 800 mm

Chandan_k — Fri, 28 Nov 2025 03:46:58 GMT

I am Using RF 200-800 with my Canon R5 Mark 2 . I was having plenty of Issues with Using AF - However Most are resolved reading through guides & community reading. However , One Thing is Still Bugging : When I start shooting Shutter Priority , and Start focussing after Zooming the Lens at 800( without aiming the Subject, I syaert with 800 straight , it Does not Auto Focus with Back Button or any Other mechanism. However, When I gradually start Focussing 500/600 and Zoom out to 800 , the Focus worked Fine and I got Good Shots. Is this a defect in my Lens or this is the way , this lens behaves ? Any responses on this will be appreciated.

Re: RF 200-800 does not focus when starting at 800 mm

Waddizzle — Fri, 28 Nov 2025 04:51:19 GMT

Sometimes you have to give the AF system a nudge in the right direction.

What does the view through the EVF, look like when you zoom out 800mm? Is there anything that is recognizable to see?

Re: RF 200-800 does not focus when starting at 800 mm

Chandan_k — Fri, 28 Nov 2025 06:37:43 GMT

nothing significant , just a mass of unfocussed background cluuter .

Re: RF 200-800 does not focus when starting at 800 mm

Waddizzle — Fri, 28 Nov 2025 11:47:08 GMT

“…nothing significant.,,”

Exactly. There’s also a setting that can disable the AF system when focus is impossible. Disabling the AF under these circumstances minimizes hunting, which can lead to oscillation under the right conditions.

SOLUTION: The user must try to prefocus the lens so that the view doesn’t look like the underside of a storm cloud.

Re: RF 200-800 does not focus when starting at 800 mm

Chandan_k — Fri, 28 Nov 2025 13:21:14 GMT

Hi Waddizie , Thanks. Is that Setting: Lens Drive on AF Impossible with Options : Stop Focus Search, Or Continue Focus Search ?

I also Own EF 70-200 , 100-400 - Surprisingly, never had seen this Issue Earlier.

Re: RF 200-800 does not focus when starting at 800 mm

SignifDigits — Fri, 28 Nov 2025 16:34:06 GMT

Out of curiosity what AF mode are you using? On the R6 M2 I can reproduce your issue with something ~1/3 FPV close and 2/3 far away with whole frame focus, but I think that may be a "feature" more than an issue. Using any of the spot focus AF variations fixes that on my R6. Many thanks to Waddizzle for pointing out then "impossible focus" option. The setting on the R6 M2 is found at AF menu 3 "Lens drive when AF impossible". Online reference says that option is on menu 4 on the R5 M2.

Re: RF 200-800 does not focus when starting at 800 mm

vantage — Fri, 28 Nov 2025 18:05:42 GMT

@Chandan_k

I've got the same camera/lens and had have that problem. I've noticed since updating to firmware version 1.2.0 I haven't had it happen. That may just be related to the specific scene.

What firmware version is in the camera? If not 1.2.0, it may be worth loading.

Re: RF 200-800 does not focus when starting at 800 mm

SignifDigits — Fri, 28 Nov 2025 20:22:02 GMT

Duh. Sorry that I missed the camera detail!

Re: RF 200-800 does not focus when starting at 800 mm

ebiggs1 — Fri, 28 Nov 2025 21:43:43 GMT

" Is this a defect in my Lens or this is the way , this lens behaves ?"

I am going to say that is the way it, and all simular super zooms lenses I have used behave also. I do not have or own the Canon RF 200-800mm f/6.3-9 IS USM lens but I do have or have owned almost every model of the 150-500mm and 150-600mm super zooms by Sigma and Tamron. Super zooms AF is a bit finicky sometimes.

Re: RF 200-800 does not focus when starting at 800 mm

rgl47 — Sat, 29 Nov 2025 19:59:01 GMT

https://community.usa.canon.com/t5/EF-RF-Lenses/Focus-Issue-RF-100-300-f-2-8-USM/m-p/576859#M39000

Having a similar issue with the RF 100-300 USM. Your description of issue on your end is also part of the issue with my lens. No constructive solutions have been offered on my post. When I zoom out to full 300mm, or 420mm with the RF 1.4 TC on, it hunts and will not focus. Never did this until about 2 months ago. I have had the lens for about 14 months now and it worked absolutely perfect and phenomenal prior to. When I move the zoom a hair under 300mm or 420mm, it works as it should.

Re: RF 200-800 does not focus when starting at 800 mm

rgl47 — Sat, 29 Nov 2025 20:04:40 GMT

FYI Chandan, the issue I am experiencing seems to have started after I did firmware updates. But, even with the most recent updated from 11/20/2025, it did not fix the issue. As many pointed out, having the stop focus search on or off should not matter. I have not changed any of the settings from when it worked normal to now when it doesn't so unless the camera/lens has a mind of its own, it would not make a difference turning it off.

Re: RF 200-800 does not focus when starting at 800 mm

rgl47 — Sat, 29 Nov 2025 20:06:59 GMT

https://community.usa.canon.com/t5/EF-RF-Lenses/Canon-RF-100-400-Autofocus-problem/m-p/407856#M25405

Here is another post from about 3 years ago with similar issue.

Re: RF 200-800 does not focus when starting at 800 mm

vantage — Sat, 29 Nov 2025 22:19:17 GMT

@Chandan_k

As I posted earlier, my RF 200-800 with my Canon R5 Mark 2 doesn't exhibit that behavior anymore. If you'd like, I can post pics of all my autofocus menu settings, you can set yours the same way and see if the problem lessens/goes away.

On the last page of the camera AF menu settings (page 7 of 7 ) is a URL to "AF Setting Guide URL."

Re: RF 200-800 does not focus when starting at 800 mm

rgl47 — Sun, 30 Nov 2025 01:11:15 GMT

Thank you, Vantage. I don't use my R5ii with the RF 100-300 f/2.8. Instead, I use the R1 and sometimes the R3. I didn't realize only certain cameras work correctly with that lens. I will however check out the url. As I mentioned, I've had my settings the same for about 14 months so for the lens to start acting up only in the last 2 months, doesn't make a lot of sense for it being AF settings. Maybe you can send me the settings anyway to double check where the issue may be?

Re: RF 200-800 does not focus when starting at 800 mm

TomRamsey — Sun, 30 Nov 2025 01:57:46 GMT

I use the lens with an R6 Mark 2 (always on shutter priority) and I have never experienced that problem.

Re: RF 200-800 does not focus when starting at 800 mm

vantage — Sun, 30 Nov 2025 02:55:10 GMT

Here's my AF settings on my R5 II. As I mentioned, I haven't seen the "does not focus" problem on my RF 200-800 for quite a while. I tried several different shots this afternoon starting at 800mm and it never failed.

Camera mode : P
Lens "Control" switch: Fully forward (AF)
Lens stabilizer switch: On

Re: RF 200-800 does not focus when starting at 800 mm

Chandan_k — Sun, 30 Nov 2025 05:18:51 GMT

Thanks. I will Use your settings and est that . Though I always Keep Eye Tracking ON When Doing animals and same for. Subject to Setect ON as Animals . However I have Observed Some other Settings Which I will try Now . Shall Provide a Feedback . Cheers

Re: RF 200-800 does not focus when starting at 800 mm

rgl47 — Sun, 30 Nov 2025 20:43:04 GMT

Thank you, vantage, for sending the settings. Although for sports and action, I use different basic settings. I don't see anything that stands out in your settings that would make a difference in my case/issue and some are the same on my end.

Re: RF 200-800 does not focus when starting at 800 mm

vantage — Sun, 30 Nov 2025 22:46:49 GMT

@rgl47,

Understood. If you're still having the problem, it may be worth duplicating my settings to see if your problem goes away. If it does, we know it's some combination of settings that causes the problem and eliminates it.

Re: RF 200-800 does not focus when starting at 800 mm

Chandan_k — Tue, 02 Dec 2025 15:31:23 GMT

The Camera Firmwire is 1.1.1 Jukly 25 Released Latest Update . I am not sure 1.2.0 applies on R5 MK 2 .... ?