Bolex FPS

ochopatas · October 21, 2005

The h16 Bolex runs for 28 seconds at 24 fps, from what people tell me and from the internet. My camera runs for 20 seconds at 24fps. Does this mean that my camera is actually running faster than 24, even though the setting is at 24, or does it just mean that...well...it runs for 8 seconds less than the average?

Edited October 21, 2005 by ochopatas

ochopatas · October 21, 2005

I don't know if it would help to add that running at 18 fps, which is marked in red, is 28 seconds.

Clive Tobin · October 21, 2005

I don't know if it would help to add that running at 18 fps, which is marked in red, is 28 seconds.

Seems to me that recent Bolexes, above serial 100401 with the desirable register claw, will shoot 16 feet on a winding which is about 27 seconds. I think the old ones with the unsteady cam-driven movement would shoot 19 feet.

Several possibilities:

Your speed dial is way off.

The cutout gears that govern how long the spring will run are mistimed.

Maybe the spring is weak so someone mistimed these gears on purpose.

Let me guess... you bought it on Ebay? :-)

Use a stopwatch and count how many frames go by in 10 seconds then divide by 10. This will be a good guide to whether the speed is correct or not.

October 21, 2005

I assume that none run as marked, ebay source. So, I get a piece of film, measured in a editing frame counter, or just count off so many frames. It could be 10 feet long or 6 feet long. Whatever, you do the math. That is loaded and single frame advanced to a certain frame with an X on it. At a full wind it is run thourgh the camera and timed. Speed adjusted, run, timed. The dial is marked where it is closest to 16 fps, 18 fps, or 24 fps. The frame counter in the Bolex is another way to count the frames. Just set it to 0 each time and stop at so many seconds and count the frames.

This helpes exposures be more correct.

A local tech told me that it is the speed governor that goes bad. I asked him why he doesn't just slap on a crystal sync moter and bypass it. He said it wasn't worth it??????? One of those moters would be a good thing I think.

Edited October 21, 2005 by Michael Carter

ochopatas · October 21, 2005

Not ebay, it is my university's camera. But they haven't used it for 10 years or so.

I noticed on the speed dial that someone etched a line into it between the 18 and 16. I just thought it was some kind of...I dunno...marker, but it ends up that that is the correct 24 fps setting.

What I did to test it is like you said, except I reset my frame counter to 0, and ran it for 1 second, see where it ended up. And lo and behold, it was approximately 24. I read someplace on the internet that a bolex improperly stored (that is, not wound down) will really ruin the spring motor and since it's more costly to repair the spring(?) it's better to just adjust by resetting the marker on the speed dial.

Thank you for your advice.