Leica's earlier R-mount 24mm — 3-cam version without ROM contacts.
The Leica Elmarit-R 24mm f/2.8 (3 Cam) is a wide-angle prime for the Leica R SLR system at Elmarit (f/2.8) aperture class. The 3-Cam version enables correct metering on Leica M bodies via the M-Adapter-R in addition to standard R bodies. Leica R mount.
f/2.8 maximum aperture. 24mm focal length (full-frame). 3-Cam coupling (Leicaflex SL, R3–R7, and Leica M via M-Adapter-R). Manual focus via SLR viewfinder. At approximately 455g. 55mm filter thread. Leica R mount.
The 3-Cam adds an M-coupling cam for metering on Leica M bodies (with M-Adapter-R). On modern mirrorless adapted use, cam type is irrelevant. The 3-Cam version typically commands a small premium for M-system users seeking metering compatibility.
On the used market the Leica Elmarit-R 24mm f/2.8 (3 Cam) is a premium wide-angle prime. Condition checks: 55mm front element, all three cam contacts for wear, aperture blade operation. Leica R mount — requires adapter for current cameras.