J9 helicoid for use in biotar 75mm

[maartenmoerman]

Would a Jupiter 9 helicoid/rear of the lens be a suitable candidate for converting an exakta mount Biotar 75mm/1.5 ? I'm just looking into what might be needed to convert such a lens to being rangefinder coupled. Anybody ideas/suggestions?

 

[lukx]

I don't think the Jupiter-9 route will work. The helicoid will travel a longer distance than required, and the coupling to the rangefinder is specific for this focal length. Your lens would not be correctly coupled across the range, even if you get infinity or 1m (either, not both) correct. I think this will be a major custom job for someone like Skyllaney in the UK.

 

[Sonnar Brian]

A J-9 mount will not work.

Contact Chris at Skyllaney. This conversion will require custom machining, is not an easy job,

 

[maartenmoerman]

Thanks! Will do.