topic Re: Unsatisfactory autofocusing with EOS C400 in Professional Video

Unsatisfactory autofocusing with EOS C400

Tobias — Tue, 02 Jun 2026 13:06:32 GMT

I’ve had the C400 for almost exactly a year now and I’m more than happy with the footage. I just have one major problem.
My Canon C400 has a major autofocus issue. I find the way the C400 handles autofocus completely unsatisfactory. What exactly is the problem? The Canon R5 works very well, but the C400 just can’t get it right.
I've tried lots of different focus settings and nothing has worked. Are you happy with it? How did you set it up?
Here’s a test I found on YouTube. It illustrates my problem quite well.
https://www.youtube.com/watch?v=7bxl9qgkukk
I often work with the Sony FX9 and the Sony FX3 as well, the Sony range is simply perfect when it comes to autofocus. You select a face and the focus locks onto that person. Why doesn’t this work on my C400?
Does anyone have a solution for this?
Thank you very much for sharing your thoughts

Re: Autofocusing with Canon C400

shadowsports — Mon, 01 Jun 2026 13:20:17 GMT

Greetings ,

I suggest you contact Canon support. They should be able to help you identify and understand the specific concerns you're having with your camera. 1-800-652-2666

Re: Unsatisfactory autofocusing with EOS C400

tgm — Mon, 06 Jul 2026 10:44:31 GMT

Same here. The C400 has serious autofocus issues. I thought it's my RF 24mm 1.4 VCM that has issues until I got the 50mm 1.4 VCM and it struggles the same way.

C400 in "People detect ONLY" mode does actually hunt to the background in perfectly lit talking head setups. It is ruining shots randomly. I'm in professional support and they couldn't solve it yet. I have videos of this behaviour if Canon is interested.

You can even test it with a hand in front of a face. "People detect ONLY" will recognize the hand as a face which is ridiculous. This is the top of the line RF cinema body with L VCM lenses which are advertised for video application. Yet this setup is buggy and far behind FX6 capabilities. C70 with cheaper STM lenses never did this in "Face only" mode. This is a C400 AF issue. Probably the same with C80?

Is Canon working on this?

Re: Unsatisfactory autofocusing with EOS C400

Tobias — Tue, 07 Jul 2026 07:27:51 GMT

Dear tgm,

I’m glad I’m not the only one with this problem. I think many people working in the professional sector face the same issue. I find it frustrating that no one from Canon ever addresses our problems. It would be great if Canon were to get involved in this discussion. The best solutions are found through dialogue. I’ll be testing the latest update today and will let you know whether the autofocus problem has improved. Unfortunately, according to the details, the latest update doesn’t include any improvements to the autofocus.

Re: Unsatisfactory autofocusing with EOS C400

tgm — Wed, 08 Jul 2026 14:38:39 GMT

My guess is that the VCM primes are more calibrated towards mirrorless. I also own a R5 Mark II and the VCM primes behave very differently and much better there.

Canon needs to readjust the communication between the cinema bodies and VCM primes. Right now I prefer the STM lenses for interview setups.

Re: Unsatisfactory autofocusing with EOS C400

easd — Fri, 10 Jul 2026 15:58:26 GMT

My C80 autofocus is also lacking compared to my R5 II. Which is weird because if their photo cameras have autofocus that works so well, why can't they share the tech? Do the photo and cinema cam engineers gate keep info from each other?

Anyway, I've been sending in feedback for years since the C70 but seems like improving the autofocus on their cinema cameras isn't Canon's priority