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- Produced LZOS, Lyktarino, Russia 1979
- Mount Leica Thread Mount (M39)
- Focal length 35mm
- Aperture range f2.8-22
- Focal range 1m to infinity
- Filter thread 40.5mm
- Elements 6 in 4 groups
- Weight 130g
- Aperture blades 5
- coated
- no click stops
Overview
The most obvious choice for its own page, the Jupiter-12 is easily the most popular accessory lens for the Former Soviet Union Leica-style rangefinders. They were produced over a period of years in a couple of different factories, this is the later black model from famed Lytkarino (LZOS) factory, who made lenses for KMZ.
Usage
The design is such that it’s self-shaded (no hood necessary), and the aperture ring is recessed inside the outer lens housing. Screwing a 40.5mm thread in means the filter becomes your aperture control.
The most difficult thing with the J12 is protecting the large mushroom-like rear element. It’s well known that minor scratches on the front of a lens have minimal effect on the picture quality; however, scratches on the rear element, particularly one that comes as close to the focal plane as this one, are generally obvious on the final image. If yours didn’t come with a cap you might be able to make one out of a film canister.
Because the rangefinders you will use this on have viewfinders designed for the angle of view of 50mm lenses, you will need a special viewfinder to insert into the accessory shoe to properly frame your subject. Focus on the window as normal, frame in the accessory finder. I use a Petri finder, it’s close enough to 35mm to be very useful. If you have more than one auxiliary lens, it’s probably best to get KMZ’s Zeiss copy multi-finder.
Special Notes
Occasionally the rear element rubs on the inside of the camera, most noticeable when mounting. Always mount these lenses by first changing focus to infinity to flatten the base of the lens housing. If you feel some resistance when screwing it in, stop, remove it, and check whether it’s rubbing against the rangefinder arm. You may lose paint from the edges of the rear element, resulting in flare. I did this the first time I mounted mine, and repainted it with flat black paint pen from Birchwood-Casey. Then I bent the rangefinder arm upward slightly on that particular FED 2 (they’re all just a little different) and made sure to always set focus to infinity before mounting it after that.
NOT COMPATIBLE with the Bessa rangefinder series, from what I understand; the rear element interferes with the shutter on those cameras. Common question.
Related Links
- LZOS, still going strong
- Alfred Klomp has a good page on the J12 at his outstanding Alfred’s Camera Page
- The great Medium Format Home has a table of FSU lens info