topic Re: EOS R100 not able to use Manual focus in EOS DSLR & Mirrorless Cameras

EOS R100 not able to use Manual focus

M1_Legend — Sun, 05 Jan 2025 22:49:18 GMT

I've looked at videos on using the manual focus and it don't have the option that they do. I have updated to the 1.1.0 Firmware.

I am using an EF 75-300mm lens with an Urth EF-RF adapter.

It displays this odd jumble of symbols at the top and says F00.

Re: EOS R100 not able to use Manual focus

deebatman316 — Sun, 05 Jan 2025 22:56:14 GMT

Are you using a Canon brand EF-RF mount adapter. If not the camera doesn’t know a lens is attached. Also 3rd Party mount adapters cause all sorts of problems. Also MF is selected on the lens for EF lenses. Some RF lenses have a switch others rely on the cameras menu system to select such choices.

Re: EOS R100 not able to use Manual focus

M1_Legend — Sun, 05 Jan 2025 23:04:01 GMT

I also have a minolta lens that uses the sony A mounting system, but canon doesn't sell Sony A - RF. Am I just SOL with that?

Re: EOS R100 not able to use Manual focus

deebatman316 — Sun, 05 Jan 2025 23:23:44 GMT

If you're using a Minolta A Mount lens nothing will be automatic. The lens in the picture is a Canon EF 75-300mm F/4-5.6 III lens. That's not a Minolta (now Sony) A Mount lens in the picture above. On a Minolta (now Sony) A Mount lens the aperture is controlled via a lever that engages with the camera body. Then AF is carried out by a motor in the camera body. Or if its a newer lens the motor in the lens AF the lens.

Re: EOS R100 not able to use Manual focus

shadowsports — Mon, 06 Jan 2025 09:51:18 GMT

Greetings,

One last setting you can try. On your camera, open the custom function menu. C.Fn4

Look for a setting called Release Shutter without lens attached. Set to enable. Re-Atempt manual photography.

The Urth adapter does not appear to be known for its reliability or quality.

Re: EOS R100 not able to use Manual focus

p4pictures — Mon, 06 Jan 2025 09:54:43 GMT

If you need assurance that this works, you need to use Canon lens > Canon lens adapter > Canon camera. If that works - and that is what Canon would test - then the problem is any part that is not Canon. Third party lens adapters are known to cause problems.

Re: EOS R100 not able to use Manual focus

FloridaDrafter — Mon, 06 Jan 2025 20:54:22 GMT

Hello, M1_Legend, and welcome to the forum!

After looking at the Urth web site, it looks like they have two (maybe more) types of EF-RF adapters. I suspect, from looking at the image you posted, the one you bought is the one they sell that has no contacts for communication between camera and lens. That is why you are getting the F00 error, the camera can't see the lens to set the aperture or AF on the 75-300. They have another that claims "with Electronics" that may work, but it is more expensive than the basic Canon brand adapter without the control ring. Without an adapter with contacts, the EF 75-300 III lens you have pictured, will not work, or any other lens that isn't fully manual for that matter.

As Rick suggested, if you have fully manual lenses, set the camera to release shutter without lens. As I mentioned, this won't help with the pictured 75-300. The best option, if it's still available, is to return the Urth adapter and follow Brian's advice and go full Canon gear. It will be more reliable.

Newton