Folks,
I'm on another quest for something which may not exist. I would like to be able to exactly time (program, so to speak) long exposures on B (bulb) with my Mamiya AFD, film and MFDB. There are gizmos all over ebay which can do this for DSLRs, but they have DSLR-specific electrical cables. I am hoping to find something that will include, or take, a standard mechanical screw-in cable release and allow me to shoot for say 40, 60, 120, 1800 seconds or whatever (the camera itself tops out at 30 seconds...it's only B beyond that).
What I picture is something like the old-fashioned Autoknips; but whereas that set a delay before pushing in the cable release plunger, I want something which will hold in the plunger for a period which I can set, and then release it. I have actually found an old movie-camera device which apparently does exactly that, but it is limited to 5/10/20 seconds exposures only...and the Mamiya can already go to 30 seconds. Are there movie-camera devices which can go longer than that?
I was also thinking along the lines of those darkroom enlarger-light timers from Meopta etc. - these can be set to switch the light on for a set number of seconds, using relays. The only problem is that they are relaying ac mains, not pushing in a plunger!
There cannot be much involved in rigging one of these darkroom timers, or even one of the DSLR timers/intervalometers, to a mechanical/magnetic relay plunger-pusher, but alas the electro-mechanics are beyond me. There might even be a market for such a gizmo - it would suit all of the motor-driven cameras out there with mechanical cable release sockets, and add a lot of functionality to them.
Any ideas/suggestions?
Thanks,
Ray