Zach Whittaker Posted October 16, 2016 Share Posted October 16, 2016 Is there an adapter that will take a Bolex Bayonet mount lens and convert it to mount a C-mount camera? I've seen a lot of adapters that go the other direction. Link to comment Share on other sites More sharing options...
Nicholas Kovats Posted October 17, 2016 Share Posted October 17, 2016 I have been obseesed with this for some time but have yet to find a third party adapter. I suspect a custom machining job is required as the FFD offset is minimal at approximately 5mm. Good luck. Link to comment Share on other sites More sharing options...
Premium Member Dom Jaeger Posted October 17, 2016 Premium Member Share Posted October 17, 2016 I think there are a number of issues, which might explain why no-one has made such an adapter. Firstly, as Nicholas mentioned, the difference from bayonet flange to C-mount flange is only about 5.5mm, which doesn't leave too much room for the material thickness of the bayonet flange and the lock ring threads. Secondly, the large diameter of a Bolex bayonet mount sitting almost flush will hit protruding parts of a C-mount Bolex turret - the centre screw, turret lever, edge lock, and any mount caps for the other 2 mounts, including the bottom locking one which is pretty important to stabilise the turret. You'd probably find a number of other C-mount cameras that have some sort of protrusions within a 40mm radius of the mount. Thirdly, the reason Bolex went to a bayonet mount for the heavy zooms of the SBM, EBM and EL era was because the weight could flex a turret and alter the crucial flange depth. So even if you custom machined an adapter and removed any protruding obstacles in order to mount a bayonet zoom, it might not be worth it for the possibly soft images or potentially damaged camera mount. Even a non-turret C-mount camera could have the front plate distorted by the weight of a heavy zoom. But in theory, it's possible, and a lens support could protect the mount. Link to comment Share on other sites More sharing options...
Nicholas Kovats Posted October 17, 2016 Share Posted October 17, 2016 Well, Zack, you lucked out with Dom's excellent overview. He is a seperlative camera engineer and technician. I will now officially put my dream to rest. Link to comment Share on other sites More sharing options...
Premium Member Simon Wyss Posted October 17, 2016 Premium Member Share Posted October 17, 2016 Good, I’d have explained the same way but Dom beat me. The Paillard-Bolex H camera was designed in 1930-31, its front and turret plates got redesigned in 1953-54 and again in 1955-56. Heavy lenses are not meant to be used with this “professional amateur” camera as it went in the publicity from 1937 on. The zoom lens challenges the older concept. A choice of lens ports on a turret has a number of advantages one must learn to appreciate. I do appreciate the following ones: Compact and lightweight primes C mount allows the use of shim rings (with older lenses that have long mounting threads) Use of the rackover system which is more easily controllable by a technician than a reflex system “Vertical” shifting of a lens to some extent Use of auxiliary equipment attached to the turret via one or two lens ports, for example a bellows holder The coolest of all turrets was known with the Askania shoulder camera of 1935, it has a spring that can be wound up and then made to revolve step by step, even while the film is running. Clack, clack, clack, clack, two revolutions. Link to comment Share on other sites More sharing options...
Jean-Louis Seguin Posted October 17, 2016 Share Posted October 17, 2016 If you happen to be talking about the later version Vario-Switar 16-100mm, Parts are available from Bolex to convert the bayonet mount to a C-mount. 1 Link to comment Share on other sites More sharing options...
fatmi mounir Posted November 14, 2019 Share Posted November 14, 2019 Hi, thanks a lot for the information. Do you have a link to find this adapter? thank you in advance. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now