TTArtisan’s latest M-mount to E-mount adapter has a focal length dial that transmits focal length info to the camera for lenses with no electronic contacts.
As reported by DPReview, the TTArtisan ME 6-Bit adapter supports all modern and legacy M-mount lenses and in addition to supporting data transmission with lenses that support Leica’s 6-bit electronic circuitry, it has the additional ability to send pre-encoded focal lengths to a camera body and “fake” the electronic communication.
If the attached lens has 6-bit electronic circuitry to send its metadata to the camera body, the adapter supports that transmission. For those unfamiliar, Leica’s 6-bit code system is the company’s method for providing EXIF data to a camera, as explained by LaVidaLeica. M-Mount lenses have electronic circuitry that tells the camera its lens information using a 6-bit code of ones and zeros. Depending on their arrangement, a camera with an optical 6-bit code reader can know what lens is attached.
But not all M-mount lenses support the 6-bit circuitry, and in those cases, the TTArtisan adapter has a separate trick that allows those lenses to still allow for the transmission of EXIF data to the camera. The adapter includes a small wheel that can be used to select a focal length which it then communicates to the camera using pre-encoded metadata.
This can be beneficial for a variety of reasons, chief of which is that the Sony mirrorless cameras use in-body image stabilization which is optimized for specific focal lengths. Without focal length information, the stabilization won’t be as effective.
To function properly, the focal length needs to be set on the adapter after it has been placed on the lens but before the entire assembly is attached to a camera. In this way, the pre-encoded focal length information will be picked up by the camera.
From the limited photos that TTArtisan has provided, it appears as though the focal length selector on the wheel tops out at 135mm. In the demonstration video above that shows how to use the adapter, 90mm, 50mm, 35mm, and 28mm settings are also shown.
At the time of publication, the company had not yet provided any additional information nor had it published the cost or anticipated availability of the adapter.