A new Megadap Leica M to Canon RF adapter will have autofocus

Mirrorless cameras like the Canon EOS R series have been a popular choice for photographers who like to use vintage glass. While there are many camera adapter options available on the market, the Canon RF mount will reportedly be getting its first autofocus-capable adapter from Megadap.

Last weekend, well-known Japanese camera store Shoten Kobo shared the first image for the Megadap M2RF lens adapter on X. The Leica Rumors account on X shared more information about the upcoming lens adapter, revealing that it will have autofocus. As far as we know, this will be the only autofocus adapter for the Leica M to Canon RF mount.

This will be exciting news for fans of vintage Leica M lenses. Having autofocus on traditionally manual focus glass should entice more users to try out Leica M lenses and other third-party brands for the M-mount like Voigtlander, Zeiss, TTArtisan, Laowa, and 7Artisan.

Currently, only TechArt produces autofocus adapters for the Leica M-Mount to Nikon Z cameras.

How do autofocusing adapters work?

If you have ever tried Leica M lenses, you will know that they are fully manual. Both the aperture and focusing are done via rings found on the lens. There is no autofocus mechanism found on the lens or the camera body.

So how does the adapter achieve autofocus on a fully manual lens? The way that it works is that the adapter moves the lens forward and back to achieve focus. The lens is first set to infinity and when the shutter button is half-pressed, the lens adapter extends or retracts to achieve focus. It is similar to how optical elements shift within the lens to achieve focus when turning the focus ring.

Any M-Mount lens (Leica or third-party) will have autofocus when used with the Megadap M2RF adapter. It is the adapter, not the lens that has the autofocusing capability.

One downside of converting manual focus glass to autofocus is that the speed and accuracy of the AF will not be comparable with lenses that have built-in focusing mechanisms. Based on our experience with the M-mount to Z camera adapter from TechArt, autofocus speed is decent but will suffer from focus hunting and occasionally misfocus. We recommend using AF Single (AF-S) mode rather than continuous AF (AF-C) on these adapters to improve accuracy.

The autofocus performance of the lens adapters also seems to depend on the weight of the lens itself. Lighter lenses tend to focus faster while heavy lenses are slower. The heavy 50mm F/.95 lenses struggle with autofocus due to their weight and shallow depth of field.

We do not know the release date or pricing for the Megadap M2RF adapter yet. We estimate the cost somewhere close to the $400 price of the TechArt TZM-02 for Nikon Z cameras. Hopefully, we won't be waiting too long for the official announcement of the Megadap M2RF.