Camera / Lens Mount Compatibility

What is a lens mount and why does it determine compatibility?

A lens mount is the physical and electronic interface between a camera body and a lens. It controls whether the lens can attach at all, whether autofocus communicates with the body, whether optical image stabilization data is shared, and whether EXIF metadata (focal length, aperture) is recorded. Modern mirrorless mounts — Sony E, Nikon Z, Canon RF, Fujifilm X — are physically incompatible with each other and with older DSLR mounts. Full compatibility requires both a matching physical flange and a supported electronic protocol.

Do lens adapters affect autofocus speed or image quality?

Manufacturer-made adapters (Canon EF-EOS R, Nikon FTZ II) preserve autofocus, image stabilization communication, and EXIF data with minimal optical impact. However, phase-detect autofocus is often slower with an adapted lens than with native glass, and some advanced AF modes — eye-tracking, animal detection, predictive sport tracking — may be limited or unavailable. Third-party adapters of lower quality can introduce optical issues such as focus shift, but well-made all-glass adapters are typically optically neutral.

Can I use a full-frame lens on a crop-sensor camera body?

Yes. A full-frame lens (such as a Sony FE lens) works on a Sony APS-C body sharing the same E-mount, but the crop factor applies — a 50mm FE lens behaves as approximately 75mm equivalent. The lens covers the sensor fully with no vignetting. The reverse — mounting an APS-C lens on a full-frame body — causes severe vignetting in the corners, or the camera automatically switches to a cropped shooting mode if it detects the smaller image circle.