topic Re: Help with movie cropping r6 mark ii and sigma 18-35 in EOS DSLR & Mirrorless Cameras

Help with movie cropping r6 mark ii and sigma 18-35

FreezeCsc92 — Mon, 05 May 2025 07:59:52 GMT

Hello, I need a little information. Basically, I have an R6 Mark II
with a Sigma 18-35.
I can't turn off movie cropping.
I have an official Canon EOS R adapter ring.
And I wanted to know if it's possible to have automatic cropping with the Viltrox EOS R?
Thx 🫡

Re: Help with movie cropping r6 mark ii and sigma 18-35

p4pictures — Mon, 05 May 2025 08:06:43 GMT

The Sigma lens 18-35mm f/1.8 is a DC lens, that’s Sigma terminology for a lens designed for crop sensor cameras. This means it was not designed to cover the whole image area of a full frame sensor. The lens reports that it is for crop cameras to the camera and the camera automatically selects crop mode.

If the Viltrox adapter does not pass that info to the camera then the camera might shoot in full frame mode, but you’d expect to see some significant vignetting of the captured images / movies.

Re: Help with movie cropping r6 mark ii and sigma 18-35

FreezeCsc92 — Mon, 05 May 2025 08:08:59 GMT

Thx for the reply

Yes, I understand, but there's no concrete information telling me that with a Viltrox adapter I won't get automatic cropping.

Re: Help with movie cropping r6 mark ii and sigma 18-35

p4pictures — Mon, 05 May 2025 08:54:04 GMT

The issue will be who owns the responsibility to decide this, Sigma - it's their lens, Viltrox - it's their adapter, Canon - it's their camera.

In such case even if the Viltrox adapter does not pass the cropping information from the lens to the camera you are still very likely to experience significant vignetting of the image. In the past I tried some older Sigma and Tamron lenses on a full-frame EOS R with the Canon adapter. Those lenses did not report they were cropped lenses and vignetting was quite noticeable at some settings. I wrote about this on my blog in 2019

https://www.p4pictures.com/2019/06/eos-r-crop-lenses-aps-c/

Re: Help with movie cropping r6 mark ii and sigma 18-35

Waddizzle — Mon, 05 May 2025 23:29:37 GMT

“ Yes, I understand, but there's no concrete information telling me that with a Viltrox adapter I won't get automatic cropping. “

Third party lens manufacturers tend to only use the EF mount, almost never the EF-S mount. If the EF mount works on all Canon DSLRs, why make one that doesn’t work on all cameras?

The bottom line is the lens has the EF mount, despite being a crop sensor lens. The camera will not automatically detect a crop lens and switch to crop mode.

Re: Help with movie cropping r6 mark ii and sigma 18-35

FreezeCsc92 — Wed, 07 May 2025 11:48:20 GMT

Okay, thanks for your reply.
So I bought the Viltrox EOS R adapter and I'll see.
I'm really looking for that strong vignetting to give a graphic style to my videos.

Re: Help with movie cropping r6 mark ii and sigma 18-35

FreezeCsc92 — Wed, 07 May 2025 11:53:45 GMT

But honestly, do you think there won't be any cropping with the Viltrox?
Does the R6 Mark II really not automatically crop directly on the camera body?
There isn't much information on this subject.

Re: Help with movie cropping r6 mark ii and sigma 18-35

p4pictures — Wed, 07 May 2025 12:06:15 GMT

You might find the vignetting changes depending on the focal length.

Re: Help with movie cropping r6 mark ii and sigma 18-35

p4pictures — Wed, 07 May 2025 12:19:04 GMT

If the lens tells the camera it's a crop lens, the camera will only work in crop mode. As you have seen with the Canon adapter this is the case, so the lens must be signalling that it is a crop lens. I would be surprised if the Viltrox adapter does not pass that same information.

Re: Help with movie cropping r6 mark ii and sigma 18-35

FreezeCsc92 — Wed, 07 May 2025 12:35:26 GMT

I saw this video that shows there's no auto crop, but it's the R6, not the R6 Mark II, so I don't know if it's the same.
https://youtu.be/qQpX4j293oQ?si=D12Lkh2srBv1aLr2

Re: Help with movie cropping r6 mark ii and sigma 18-35

Waddizzle — Wed, 07 May 2025 23:02:12 GMT

The automatic crop mode is initiated by the lens mount itself.

There is no exchange of data between camera and lens. DSLR lenses don’t have these smarts in their firmware. The camera firmware , however, the camera IS able to detect whether the attached lens has an EF mount or an EF-S mount.

As I pointed out earlier, third party manufacturers use the EF mount for all Canon DSLR lenses. The camera will not enter crop mode with third party DSLR lenses.