Thank you for using Tokina lenses. We have thoroughly tested all current Tokina interchangeable lenses (Canon EF mount) with the Canon EOS R mirrorless camera and the Canon EF-EOS R mount adapter. The results confirm that the current Tokina lens models showed no issues in general operations, with the following exception:
Issue: the image Cropping/Aspect ratio would be fixed at "1.6x (Crop)" and cannot be set at "Full (3:2)".
We are currently preparing a firmware to fix the issue, which will be specifically notified about in due time.
Furthermore, when using Tokina APS-C format lenses (Tokina DX lenses), in case the Cropping/Aspect ratio is set otherwise, it is necessary to reset it on "1.6x (Crop)" manually. When shooting with a different Cropping/Aspect ratio setting, vignetting is likely to occur.
For any questions about compatibility of Tokina interchangeable lenses with Canon EOS R mirrorless cameras, please contact us via contact form.