topic Re: Vivitar lens won't work on an EOS R with adapter in EF & RF Lenses

Vivitar lens won't work on an EOS R with adapter

eapples — Sat, 08 Aug 2026 18:37:46 GMT

Vivitar 8mm 1:3.5 Lens On a Canon EOS R With a Lens Adapter

Hello: I apologize if I've already posted about this. I have a Canon EOS R camera. I use a Canon adapter so that I can continue using the lenses I had on my Canon EOS Rebel. One of those lenses is a Vivitar 8mm fisheye lens. It works perfectly on the Rebel, but will not function at all on the EOS R. When I tried using the lens on the mirrorless camera, nothing worked -- the shutter button would not work; I could not get an aperture reading, nor could I get a reading on any setting on the camera. I am a technology dinosaur, so my eyes glazed over when I tried to research the issue since I encountered a lot of technojargon. I am reaching out to the Canon community for some guidance. Thank you in advance for your help.

Re: Vivitar lens won't work on an EOS R with adapter

Waddizzle — Sat, 08 Aug 2026 19:48:33 GMT

If it is fully manual lens and the aperture displays as F00, then you need find the following menu setting.

Release Shutter Without Lens

The factory default setting is Disabled.

Re: Vivitar lens won't work on an EOS R with adapter

Waddizzle — Sat, 08 Aug 2026 19:51:40 GMT

I recommend only using Av or M modes with fully manual lenses. Avoid shooting modes that require the camera to control the aperture.

Re: Vivitar lens won't work on an EOS R with adapter

eapples — Sat, 08 Aug 2026 21:23:55 GMT

Yes, it is fully manual, and the reading is F00. I will try your recommendation, and I will report back to you. Thank you.

Re: Vivitar lens won't work on an EOS R with adapter

eapples — Sat, 08 Aug 2026 21:25:18 GMT

Others have recommended the same. I will report back to you when I've had a chance to play with the camera and lens. Thank you.

Re: Vivitar lens won't work on an EOS R with adapter

Waddizzle — Sat, 08 Aug 2026 23:31:56 GMT

“

Others have recommended the same. I will report back to you when I've had a chance to play with the camera and lens. Thank you.“

Oh, yeah! When using Av mode, you should be able to set an Av value. Make it match the lens setting.

Re: Vivitar lens won't work on an EOS R with adapter

eapples — Sun, 09 Aug 2026 11:22:02 GMT

Hello (again): Yes, your recommendation worked perfectly. However, there's a vignette that appears, and it's weird -- a rectangular surrounded by a round. I can live with that. At least, now I have the lens working on the mirrorless camera. Thank you.

Re: Vivitar lens won't work on an EOS R with adapter

Waddizzle — Sun, 09 Aug 2026 16:54:48 GMT

“ However, there's a vignette that appears, and it's weird -- a rectangular surrounded by a round. “

What is the exact model number of the lens. It may not have been designed full frame, 35mm film.

Re: Vivitar lens won't work on an EOS R with adapter

eapples — Sun, 09 Aug 2026 17:32:24 GMT

The lens has the EFS designation, so I know it's not made for a full frame camera -- I was using it on my Canon EOS Rebel.

Re: Vivitar lens won't work on an EOS R with adapter

ebiggs1 — Mon, 10 Aug 2026 16:15:31 GMT

The R camera does not know it is a crop lens since it doesn't know anything about the lens.

Re: Vivitar lens won't work on an EOS R with adapter

shadowsports — Mon, 10 Aug 2026 16:41:53 GMT

@eapples ,

Let's take this further.

Try enabling crop mode on the camera's shooting menu. This might help to minimize or eliminate the vignetting you are seeing using the EF-S lens on a full frame camera. Also worth noting, using this lens on your camera will reduce its 30 megapixel image capture capability to approx 11 megapixels. Just be aware of this.