Zeiss Opton 50mm f/1.5 Sonnar, Post War, originally made for the CRF system.
These are the new Sonnar designs of the 1950’s, an evolution over the Jena series.
These Sonnars are known to be sharper in the centre then the Jena variants, and have a unique aperture blade system that helps mitigate the focus shift.
These Sonnars traditionally have been very hard to convert over to Leica M with full RF coupling. Their optical blocks are much larger then the equivalent Jena Sonnar formulas.
We’ve designed a special Omnar body to take these Zeiss Opton Sonnars and rehouse them for Leica RF usage.
The RF cam system on these lenses is the same as the one we developed for the Bertele 5cm f/2 lens. Typical CRF to LM adapters made by various manufacturers can not take each formula’s unique EFL rating into consideration (and thus why many of these adapters often cause the installed Sonnar to front or back focus). The Omnar lens and its unique RF cam is made specifically for this lens specimen, matching the changing EFL ratings of this particular copy to ensure accurate RF focus wide open at f/1.5 all the way down to 0.65m MFD.
This particular copy has a Gloss Black Lacquer finish with brassed highlights. Its a one-off unique finish, only one like this.
Optically, the glass is in very good condition, a few minor marks. Its a very sharp iteration of the Sonnar formula and can be shot wide open even on Leica M11 with fantastic results. Aperture blades are clean from any oil/ grease. The optical block was serviced when converted.
Lens comes with a gloss black lacquer painted Zeiss-Opton vintage push on front metal cap, and a rear M cap.