EOS R8 w/ Sigma & Tokina lenses - Limited size and aspect ratio options, heavy vignetting

[AritraNath]

Hi all, just got a new Canon R8 body, and on setting up I am facing several issues. Please help.

I am using the Canon R8 with a Viltrox adaptor and Sigma 17-50 f/2.8 and Tokina 11-16 f/2.8 lens. Below are the issues:

1. While trying to set 'Image Quality', the image size is showing as 3744x2496 instead of 6000x4000 for both Raw and JPEG.

2. Under JPEG, only L and S2 are enabled, with rest of the options like M and S1 disabled for selection and grayed out.

3. Under 'Cropping/aspect ratio' only 1.6 (1.6x crop) is available for selection. Rest of the options (Full, 1:1, 4:3 and 16:9) are disabled for selection and grayed out. This issue is only when the Sigma lens is on.

4. On selecting 'Cropping/aspect ratio' as Full with the Tokina 11-16 f/2.8 lens on, I am getting heavy vignetting both from the EVF and LCD, as well as in the Image. This goes away after I zoom 15mm.

[p4pictures · Accepted solution]

The issue is that these lenses were designed to be used on a camera with an APS-C sized sensor. As such they weren't designed to cover the larger outer area of a full-frame sensor.

It appears that the Sigma is reporting to the camera that it is a lens for an APS-C camera, and so the camera automatically selects 1.6x crop mode, resulting in lower resolution. Also the camera cannot be changed back to full-frame since it knows the lens is not suitable for full-frame.

The Tokina is similar, but it does not tell the camera that it's only for crop cameras, so the camera allows full-frame to be used, but now you see that the lens cannot cover the edges of the full-frame sensor, and so you get vignetting unless you use 1.6x crop mode. 

When the lenses were designed for APS-C size sensors (22mm x 15mm) the lens could be made smaller and lighter by not needing to cover the whole area of a full-frame (36mm x 24mm) sensor. But you have now found the limitations of these lenses.

All Canon EF-S lenses used on the mount adapter, and Canon RF-S lenses correctly report that they are for crop sensor so the camera switches automatically to crop mode and cannot be changed back to full-frame.

[FloridaDrafter]

I do not know either lens, but it's likely they are made for an APS-C (crop sensor) camera. The R8 is full frame. You will need to use lenses made for the EF mount not EF-S.

Newton

[AritraNath]

I believe both of them are EF lenses because they worked just fine with canon EF mount.

[jrhoffman75]

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@AritraNath wrote:

Hi all, just got a new Canon R8 body, and on setting up I am facing several issues. Please help.

I am using the Canon R8 with a Viltrox adaptor and Sigma 17-50 f/2.8 and Tokina 11-16 f/2.8 lens. Below are the issues:

1. While trying to set 'Image Quality', the image size is showing as 3744x2496 instead of 6000x4000 for both Raw and JPEG.

2. Under JPEG, only L and S2 are enabled, with rest of the options like M and S1 disabled for selection and grayed out.

3. Under 'Cropping/aspect ratio' only 1.6 (1.6x crop) is available for selection. Rest of the options (Full, 1:1, 4:3 and 16:9) are disabled for selection and grayed out. This issue is only when the Sigma lens is on.

4. On selecting 'Cropping/aspect ratio' as Full with the Tokina 11-16 f/2.8 lens on, I am getting heavy vignetting both from the EVF and LCD, as well as in the Image. This goes away after I zoom 15mm.

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You need to read the manual if you are going to be successful with your new camera.

Canon : Product Manual : EOS R8 (start.canon)

[p4pictures · Accepted solution]

The issue is that these lenses were designed to be used on a camera with an APS-C sized sensor. As such they weren't designed to cover the larger outer area of a full-frame sensor.

It appears that the Sigma is reporting to the camera that it is a lens for an APS-C camera, and so the camera automatically selects 1.6x crop mode, resulting in lower resolution. Also the camera cannot be changed back to full-frame since it knows the lens is not suitable for full-frame.

The Tokina is similar, but it does not tell the camera that it's only for crop cameras, so the camera allows full-frame to be used, but now you see that the lens cannot cover the edges of the full-frame sensor, and so you get vignetting unless you use 1.6x crop mode. 

When the lenses were designed for APS-C size sensors (22mm x 15mm) the lens could be made smaller and lighter by not needing to cover the whole area of a full-frame (36mm x 24mm) sensor. But you have now found the limitations of these lenses.

All Canon EF-S lenses used on the mount adapter, and Canon RF-S lenses correctly report that they are for crop sensor so the camera switches automatically to crop mode and cannot be changed back to full-frame.

[FloridaDrafter]

Thanks for filling in what I left out, Brian! I was putting biscuits in the oven and just wanted to get things started 😁

Newton

[AritraNath]

Thank you Sir. That clears out the confusion.

[deebatman316 · Accepted solution]

The lenses you listed mechanically have an EF Mount but they're only designed to cover the APS-C image circle. All 3rd Party manufacturers use the Full Frame EF Mount with an APS-C image circle. Only Canon makes EF-S lenses. Also Sigma uses DC for APS-C and DG for Full. Tokina uses DX for APS-C. Your camera is working correctly you need to look into Full Frame lenses whether that be EF or RF from Canon. To use your camera to its full potential. Or any other 3rd Party designed for Full Frame sensor coverage. @p4pictures some sigma lenses do report that they're made for APS-C coverage even though they physically have a Full Frame EF Mount. That particular lens doesn't work well with newer cameras from my experience. I personally owned a copy of that and it had IS tug of war or it had focus pulsing on newer cameras that includes DSLR bodies.

[AritraNath]

Thank you all. As I previously heard both these lenses worked just fine with full frame DSLRs (EF mount), I thought they would work fine in the R8 with an adaptor.

Just upgraded from 80D and got the R8 body only, hoping to re-use the old lenses. Now I need to buy full-frame lenses for the R8. 

[deebatman316]

1st Party EF-S lenses from Canon won't physically mount a Full Frame DSLR or an EOS AF SLR camera. EF-S is not just a designation for APS-C lenses. EF-S is a separate crop sensor ONLY DSLR Mount. Those 3rd Party lenses will mount a Full Frame DSLR and cause vignetting. The danger with crop sensor DSLR lenses on a Canon Full Frame DSLR is that the mirror could collide with the mirror in a Full Frame DSLR camera. EF-S lenses protrude further into the camera body than an EF lens does. So NEVER under ANY circumstance attempt to use a 3rd Party APS-C lens on a Full Frame Canon DSLR ever.

EOS APS-C DSLR camera mounting indexes