Sigma Mount Converter MC-21, Canon EF-L to EF Mount, Increases Lens Compatibility

The Sigma MOUNT CONVERTER MC-21 lets photographers mount Canon EF or Sigma SA lenses on L-Mount mirrorless cameras while preserving autofocus, aperture control, EXIF metadata, and in-camera lens corrections. Built with a metal body, flocked interior, and a removable 1/4 inch-20 tripod socket, the MC-21 is engineered to maintain image quality and workflow integrity when migrating to L-Mount systems.

Designed by Sigma with preloaded lens data and an LED compatibility indicator, the MC-21 offers broad, practical compatibility across many EF and SA lenses. It supports AF-S autofocus and auto-exposure, in-camera correction data such as vignetting and distortion, and firmware updates via compatible bodies or Sigma tools.

Benefits

• Reuse existing EF and SA lenses on L-Mount cameras, saving cost on new lenses.
• Maintain stills autofocus performance with AF-S and reliable auto-exposure.
• Preserve EXIF and in-camera corrections for a clean, streamlined editing workflow.
• Reduced internal reflections from flocked interior, preserving contrast and detail.
• Integrated tripod socket secures heavy telephoto lenses without extra collars.
• LED indicator and preloaded profiles simplify compatibility checks and reduce setup time.

Applications

• DSLR to mirrorless migration, allowing Canon EF or Sigma SA lens owners to adopt L-Mount bodies.
• Wildlife and sports photography, using tripod support for heavy telephoto lenses.
• Studio and commercial stills work requiring preserved EXIF and lens correction data.
• Hybrid shooters using EF glass for video and stills, with caveats on continuous AF.
• Rental houses and pros offering cross-mount flexibility for client shoots.

What's Included

• 1- Sigma MOUNT CONVERTER MC-21 adapter
• 1- Removable tripod socket, 1/4 inch-20 female
• 1- Attachment/detachment tool for tripod socket
• qty- Front and rear caps (where supplied by retailer)

Why Choose MC-21

The MC-21 is Sigma engineered to provide a high level of electronic compatibility with many EF and SA lenses, including preloaded lens correction data and EXIF retention. Its metal build and flocked interior protect image quality, while the removable tripod socket adds practical stability when using heavy telephoto lenses. The LED indicator and firmware update support make it a pragmatic choice for photographers migrating to the L-Mount ecosystem.