Shutter speed of non reflex Bolex?
Posted 10 April 2007 - 08:00 AM
Posted 10 April 2007 - 03:13 PM
If it was made before serial number 100401, the H16 has a 190 degree aperture shutter.
If it has a serial number higher than 100401, the non-reflex H16 has a 144 degree shutter. From there you can just do the math for the FPS... Exposure Time = (fps x 360) / (Shutter Angle°)
You can also find info on shutter angles for H8 and H16 cameras on my website.
For exposure times with single frame filming (on non-reflex H16 cameras), when the I-T lever is switched to Instantaneous :
< SN 100401 (190 shutter) -- 1/20sec when the speed dial is set to 8fps; 1/25sec at other speeds.
> SN 100401 (144 shutter) -- 1/25sec when the speed dial is set to 8fps; 1/35sec at other speeds.
Why the difference between exposure times at 8fps and other speed settings when shooting single frames? I don't know.. that info comes from exposure times published by Paillard. But I've stuck to the 1/35 second rule (later non-reflex cameras don't have an 8fps setting) and have always gotten proper exposures (assuming I took a proper light reading).
Edited by Michael Tisdale, 10 April 2007 - 03:14 PM.
Posted 10 April 2007 - 04:30 PM
It's because the governor is still connected... They are being a little lazy with the technical description for most Bolex users now (who have an active interest in film) as opposed to the hordes of people who used to use them for home-movies who probably had much less interest in the actual mechanics...
Why the difference between exposure times at 8fps and other speed settings when shooting single frames? I don't know..
It should really read something more like: at 8fps your single frame will give you 1/20th, as you increase the fps it will tend more towards 1/25th ...