How stable should a clockwork camera be?
Posted 23 June 2008 - 02:48 PM
I just picked up a Kodak K-100 with an underwater housing off Ebay. I bought it mainly for the housing, but the more I read about the camera, the more I think this could be a cool little camera to use.
I have opened up the front, widened the gate and recentered and adjusted the turret mount and run some film through without any scratches.
My question is about how the camera sounds when running. It seems to fluctuate in speed - rythmically. Or something in the mechanism changes pitch rythmically - it is hard to tell. It is not a lot, but it seems to be at a rate of a little slower than once per second cycle at 24fps. This also seems to coincide with the foot counter's movement. It does not rotate smoothly, rather ticks like a second hand on a clock. And it follows the rythm of the sound. The more film I have run through, the less pronounced it sounds, I think.
I haven't opened up the spring motor side yet. Thought I'd do that to give some oil to the old thing (it has a "serviced by Eastman Kodak 1966" - sticker inside, so maybe it deserves some attention :-)
Does anyone know if any part of the machanism can cause this kind of fluctuations in speed? I have a K-3 as well, and that sounds smooth .... ehhmm, maybe not the right word but at least makes the same noise all the time;-)
Any input or ideas are appreciated.
Posted 23 June 2008 - 05:29 PM
Posted 24 June 2008 - 10:13 AM
I'll try to get hold of an adjustable strobe. Do you simply place it one side and look through by eye?
Posted 24 June 2008 - 11:07 AM
I have a K-100 and have run a decent amount of film through it. I would say mine sounds even and normal in terms of any clicking during filming. It does not vary in any way except when reaching the end of it's wind (which as you know lasts about a full minute). In other words the sound is the same at 5 seconds as it is at 25 seconds. The pitch and rhythm don't change. I just shot some footage of the Cubs vs. Sox.
The strobe thing sounds interesting. I'd be interested in your results.
Posted 24 June 2008 - 01:45 PM
My camera also does slow down at the end of the wind, depending on its mood... My K-3 is even until it cuts - it is nice to have it cut rather than waste film on a slowly winding down camera. The 1 minute wind is exactly what I really like about it - I measure between 50 and 55 seconds before the slow-down. Depending on the "mood" , the camera will run for another 0-15 seconds. I guess a good clean and lube of the drive mechanism may even help the cut-off-at-low-tension feature (I don't know how that works yet, but I just received both service and user manuals for the k-100)
The more old film I run through the camera, the more this variation in speed seems to fade - or maybe it was in my head all along ;-) I guess it could be some dirt/grease loosening after sitting in a garage for 20-40 years...?
I am really looking forward to seeing some real footage out of this camera, and if it works well, I will post photos from my s16 "hack job" as well...
Posted 24 June 2008 - 03:32 PM
I checked the speed of my K3 with one accurately set to 25Hz. The markings on the camera dial were quite a bit out, so I was able to remark where it should be.
In my case I was able to remove the lens and look at the mirror shutter by strobe light. I was able to tell that my camera drifts by about 1fps across a full wind.
If the variation in speed you're experiencing is a quick blip before returning to the 'proper' speed again, then it might not be easy to tell even using a strobe, depends how much variation there is I suppose, and how long it lasts for.