Sigma MC21 mount converter
Leica,  News

Sigma introduce MC-21 Mount Converter for L mount bodies

Sigma has introduced the MC-21 mount converter for mirrorless L-mount bodies, at the time of writing includes the Leica SL/TL and the new Panasonic S1 and S1R.

There are two versions of the converter, the £249.99 EF-L allows Canon EF mount lenses, including Sigma lenses with EF mount to attach to L mount bodies.

Priced at just £99, the second, SA-L version, allows Sigma lenses with the SA mount to fit the same bodies.

Sigma has confirmed the new converter has compatibility with 29 Sigma full-frame and APS-C lenses with the latter automatically enabling the auto-crop feature on full-frame bodies. Other models are not guaranteed to be fully compatible.

Lens correction profiles and autofocus and aperture control data are all stored for Sigma lenses but it’s unlikely that the data will be usable with Canon lenses. An onboard LED confirms the mounted lens’s compatibility and is also used to notify the user when a firmware update is required for older lenses.

At the time of writing, it’s not clear how the LED is powered, however, Sigma UK has confirmed that the tripod foot has no electronics and that it is removable by undoing two hex screws.

Both versions of the MC-21 will be available by the end of April 2019.

Sigma MC-21 mount converterCheck pricing and availability

WEX Photo (Pre-order)

B&H Photo (US) 


This is a shrewd move by Sigma as although the company has announced 11 Art series primes with a native L-mount, the introduction of an EF converter allows any existing Canon users with Sigma lenses to switch relatively pain-free to an L-mount body. Although they don’t say so in their press release, a large number of Canon EF lenses will also be compatible and this will not be overlooked by any potential switchers.

The same can be said of the MC-11 (WEX Photo / B&H Photo (US) – affiliate links), allowing Canon EF fit lenses to be mounted on the Sony a7/a9 series and is my recommended adaptor of choice.

Sony, Canon and Nikon have mount converters to make the take-up of their new mirrorless models more convenient so the idea of using a converter is more or less commonplace.

Although principally stills cameras, the Leica SL is well-equipped for video capture, and the untested Panasonic S1 is highly promising. This is likely to confound Canon DSLR users not already invested in the excellent but pricey EOS-1DX Mk II, the replacement for the filmmaker’s DSLR of choice, the EOS-1Dc.

While most if not all the big-name review sites have concentrated on the stills side of the new Nikon Z series, the system is highly video-centric, much more so than Canon’s hugely likeable RF system, to date at least. Part of this is to prevent competing with their own DSLRs but with them (Nikon), Sony, Leica and Panasonic all offering highly competent video Canon will have to respond.

Press release

The SIGMA MOUNT CONVERTER MC-21 allows SIGMA SA mount and SIGMA’s CANON EF mount interchangeable lens owners to use their lens investment on L-Mount camera bodies. The converter allows more freedom of choice for L-Mount cameras from SIGMA, Leica Camera and Panasonic, enhancing the extensibility of the L-Mount system.

1. Effective use of lens investment
Attaching the MC-21 to your collection of SIGMA SA mount and SIGMA’s CANON EF mount compatible lenses※ allows them to be used as L-Mount system lenses, promoting the effective use of valuable lenses already owned.

※See the list of compatible lenses below.

2. 29 interchangeable lenses available to be used for L-Mount cameras
The MC-21 increases the number of interchangeable lenses manufactured by SIGMA that can be used with the L-Mount system by 29 lenses. Compatible with the autocrop function, mounting APS-C size image circle DC lenses to a camera body equipped with a 35mm full size sensor still allows immediate use for shooting.

※ The MC-21 is not necessary for native L-Mount lenses.
・Cannot be used in combination with teleconverter.
・Operations using other non-compatible lenses are not guaranteed.

  1. Fast and accurate auto focusHigh precision AF photography in AF-S mode is achieved.* Not compatible with AF-C mode.
  2. Simple interface
    Whether the mounted lens is compatible or not is instantly visible from the color and the on/off of the MC-21’s built-in LED. The LED also notifies the user when a lens firmware update is available.
  3. Lens data is pre-loaded
    Running the data pre-loaded in the MC-21 for each lens by the special control program, autofocus and aperture control have been optimized. Regarding lenses to be released in the future, data for operating these lenses via the MC-21 will be stored in the lens. It means no firmware updates of the MC-21 will be required to use those new lenses. In addition, the MC-21 also supports correction functions of camera such as peripheral illumination, chromatic aberration of magnification, and distortion.

Other features

●Comes with a tripod socket
Equipped with a socket for attaching the tripod※. Lenses not equipped with a tripod socket can be used by mounting the tripod to the MC-21.※ The tool supplied makes attaching/detaching possible.

●The inside surface of the barrel is covered with flocking to eliminate internal reflections.
To prevent a reduction in lens performance due to internal reflections, the inside surface of the barrel is covered with flocking.

●Inclusion in Exif data
Information such as lens type, focal length, F number, and other tags are embedded as Exif data in each image file.