Mechanics: An all brass, custom body has been made to convert this 28mm Biogon to Leica M usage with full RF coupling. This lens is a prototype of ours. It has some chrome plated and some antique brass parts, using an all brass internal helicoid and RF cam system. The aperture control uses ‘coloured dots’ to signify aperture values.
Black = f/2.8
Red = f/8
White = f/4, 5.6, 11, 16, 22…etc.
Its pretty easy to figure out which dot is which since f/8 is red.
We made this lens before we fully developed our internal laser engraving capabilities, as mentioned above, it was a prototype. But none the less, fully works and is a very unique one-off creation. There will never be another 28mm Biogon lens like this one.
The lens is able to focus from Infinity to 1m and contains the original E46 front filter, the only part we kept from the original CG lens aside from the optics and front engraved ring. There is a strip of black NAPA leather around the lens also, which matches the leatherette used on various Leica M cameras.
Optics: Near Mint. There are no discernible marks we can see. No haze, no fungus.
Lens underwent an optical centering and collimation during conversion. This means we adjusted, rotated and moved the internal elements until we achieved as sharp and as accurately calibrated optical formula as possible while evenly distributing the abberations. Its important to note this, because most lens services will not perform this. Thus, you are getting a very sharp and optically centered copy of this lens.
Lens has been tested on the higher resolution sensors (40mp+), and wide open the sharpness is very impressive.
Included with the lens is a custom made rear M cap, to ensure the protruding rear element is protected, and a front original Contax cap.
A complimentary E46 Tiffen UV filter is included with the lens also.