adapting a C-mount lens to a Zorki 4

[Gianfranco_R]

Hi to everyone! I'm just new member here on RF! and I take the occasion to present myself! I'm Gianfranco, 23years old, from Bari, Italy! I have to make you a question, I joust bought a Navitron 75mm f1,3 on ebay, it arrived some days ago... well, It's a tv lens, so it's C mount... Since I'm not loocking for closeup shots I would like adapting this lens to the M39 mount, so I could use it on my Zorki 4 and on my Fed 5b!! I did some calculus of compensating the different flange focal distance, and I would be able to make an adapter for the mount... what worries me is how to focus with this lens!! HELP please! 🙂

 

[bmattock]

Hi to everyone! I'm just new member here on RF! and I take the occasion to present myself! I'm Gianfranco, 23years old, from Bari, Italy! I have to make you a question, I joust bought a Navitron 75mm f1,3 on ebay, it arrived some days ago... well, It's a tv lens, so it's C mount... Since I'm not loocking for closeup shots I would like adapting this lens to the M39 mount, so I could use it on my Zorki 4 and on my Fed 5b!! I did some calculus of compensating the different flange focal distance, and I would be able to make an adapter for the mount... what worries me is how to focus with this lens!! HELP please! 🙂

I think you are going to have some problems. If this is a true 'C' mount lens, the flange-to-film distance is 17.526 mm, while a LTM camera flange-to-film distance is 28.8mm. This means that the lens must be sunk into the camera body nearly 10mm.

I think you may also find that the image circle cast by the lens you have will not cover a 35mm frame of film. So even if you manage to create a mount that holds the lens nearly 10mm into the body of the camera, the resulting image will be a small circle in the center of the 35mm film frame.

I'm sorry, but c-mount lenses are not really adaptable to 35mm film cameras.

 

[Gianfranco_R]

yes man I know this, but suppose I just want a circle in a 35mm frame... how could I combine this lens to the zorki RF??