topic Re: 35 mm lens showing closer than 35mm in EF & RF Lenses

Sigma 35 mm lens showing closer than 35mm on EOS R6

ttracy — Tue, 18 Feb 2025 14:05:09 GMT

I'm not sure the best way to describe what is happening but i'm going to do my best! haha

I shoot on a Canon R6 body and have the adapter for my Sigma art 35mm lens. recently i have noticed that when i look through the viewfinder my subjects are closer than the 35mm. I have tried googling the problem, i updated the filmware i have no idea what is happening so any help would be appreciated!

Thank you so much!

Re: 35 mm lens showing closer than 35mm

shadowsports — Mon, 17 Feb 2025 01:35:11 GMT

Greetings,

What kind of adapter are you using on your R6? Is it a Canon brand adapter.

I think you should verify the EXIF data. You should be able to do that in a third party editor or EXIF reader. This is one method you can use to determine the focal length the camera is capturing in.

Re: 35 mm lens showing closer than 35mm

ttracy — Mon, 17 Feb 2025 02:11:23 GMT

Yes its a canon adapter! It hasn't always done this, it just started recently!

Re: 35 mm lens showing closer than 35mm

kvbarkley — Mon, 17 Feb 2025 02:23:15 GMT

Are the images affected? Could it be remembering a zoom setting from lens to lens?

If the size of the saved image file is a factor of 1.6 less it could think the one 35mm is a "-S" lens.

Re: 35 mm lens showing closer than 35mm

AtticusLake — Mon, 17 Feb 2025 10:01:30 GMT

... my subjects are closer than the 35mm. I have tried googling the problem,

I'm afraid I don't really understand what problem you are having. According to the specs I found, your lens's close focus distance is 30 cm -- i.e. 300mm. If your camera is closer to the subject than that, then it should not be able to focus. The solution is for you to move the camera farther away. https://www.sigma-global.com/en/lenses/a021_35_14/specification.html

Your post seems to be confusing focal length and focus distance, so maybe that's the issue. Your lens is a "35mm", meaning that its focal length is 35mm. And yes I know it's called "focal length", but it really has nothing to do with how close your lens can focus. It's really more like "magnification" -- though that isn't technically right. Compare it to 50mm, which would be your "standard" lens, and you can see that it's a bit wide angle.

As I said, this really has nothing to do with how close the lens can focus. My 35mm lens focuses down to ~~25mm~~ 50mm. Some 35mm lenses might only be able to focus much farther than that. This isn't a problem; you just can't put the camera closer to the subject than that close focus distance. You will find your lens's close focus distance in its specs.

If you're having some other problem, maybe you could state clearly what that is, or even provide sample pics.

Re: 35 mm lens showing closer than 35mm

ttracy — Mon, 17 Feb 2025 15:52:47 GMT

This could be the problem! It was fine until I used my 24 to 70 lens and then switched back to my 35! Idk if that is possible?

Re: 35 mm lens showing closer than 35mm

ttracy — Mon, 17 Feb 2025 15:55:16 GMT

The above two answers make the most sense as I know my lens very well and it’s recently a different focal length as I have noticed for recent shoots. I wasn’t sure how to explain the issue other than the way I worded it without actually physically showing someone.

Re: 35 mm lens showing closer than 35mm

kvbarkley — Mon, 17 Feb 2025 16:07:35 GMT

Compare the image dimensions of photos taken with both lenses.

An L-Sized image with an RF lens is 5472 x 3648

An L-Sized image with an RF-S lens is 3408 x 2272.

Re: Sigma 35 mm lens showing closer than 35mm on EOS R6

ebiggs1 — Tue, 18 Feb 2025 15:17:01 GMT

First updating the FW won’t make any difference. Second how much difference and what two cameras are you using for comparing to make your assessment?

Re: 35 mm lens showing closer than 35mm

kvbarkley — Tue, 18 Feb 2025 15:31:44 GMT

You can take a picture of the LCD showing the problem.