Carl Zeiss Jena 5cm f/1.5 Sonnar which has been fully restored and converted to Leica LTM with RF coupling. Lens also includes a 6-bit code LTM to M adapter.
Mechanics were ultrasonically cleaned, polished, and reassembled using synthetic low-outgassing lubricants. Aperture control system was also rebuilt and all old grease/ oil purged out of the assembly. Helicoid was polished for smooth focus action. The lens focuses from 1m to Infinity with RF coupling to drive the rangefinder system on Leica rangefinder style cameras. The optical block mechanics of this lens is all brass, including the aperture control ring. As such, this lens is a tad heavier than the later T-coated LTM Sonnars that use all aluminum mechanics.
Optics were cleaned and centered for maximum sharpness. The optics are of the early single coated/ uncoated formula. The front element appears to have a early/ primitive form of single coating, while all the internal elements and rear element set are uncoated. There are some micro-air bubbles inside some glass elements, which is very typical of these early Carl Zeiss Jena lenses and reflect the German Schott glass recipe used during that time.
Optical condition wise, the lens is in excellent condition. The front element shows no scratches, coating or cleaning marks. The rear element is also in excellent condition.
Lens has been calibrated for f/1.5 aperture. From f/4 thru f/5.6 there is focus shift (aka: sonnar focus shift).
The lens has been optimized also for closer focus/ portrait distances accuracy. To achieve infinity for landscape type of photography, its best to stop down to f/2.8 or smaller aperture setting, which uses the Sonnar focus shift to move the focal plane outward towards infinity. When set to f/1.5 and infinity, the lens focuses just shy of infinity by design (this is to prevent the lens from focusing past infinity once it becomes stopped down, as the sonnar focus shift moves the focal plane outward).
Lens includes a front push on metal cap and a rear plastic M cap. It also includes a vintage 40.5mm uncoated filter in a brass/ chrome housing and a vintage screw on metal hood as seen in some of the pictures.
Like all our Sonnar restorations, it includes a 1 year warranty also on all work.