Photography with movie film is the same as photography with a still camera, it's still a function of film speed vs f/stop (aperture) vs shutter speed. Usually, movie cameras are set for one shutter speed, so the f/stop is set based on film speed (and perhaps adjusted by neutral density filters if they wish there was less light).
So OK, in this case you'll have a fixed f/stop, so you need to determine the shutter speed. What's the film's ISO? You're f/stop won't be 2, it will be more like 1/300 or something. There are calculators online where you can figure out the time exposure for that f/stop, all you need to do is light the scene and use your regular still camera as a light meter to get a starting exposure (which you then extrapolate out with the calculator). If you're experienced you can also do the extrapolation in your head, but I'm not getting that impression from your posts.<g> As for making an animated film, you're going to need a box that simulates a real movie camera, with chambers for the feed and take up reel and the film passing through a "gate" that will keep the registered and not expose adjoining frames. That's the tricky part, but if you are using 16mm film, how many sprocket holes to a frame, one? If you had something inside that "clicked" as a sprocket hole passed over it, you could get a rough registration, the same way a Watson bulk film loader clicks every eight sprockets to let you know you've loaded one frame of 35mm film. This sounds real interesting, if you get this even close to being off the ground, I have an animation teacher friend that would be interested to hear about it. |-----Original Message----- |From: pinhole-discussion-admin@p at ??????? |[mailto:pinhole-discussion-admin@p at ???????]On Behalf Of Bernard P |Roddy |Sent: Wednesday, November 15, 2000 6:30 PM |To: pinhole-discussion@p at ??????? |Subject: Re: [pinhole-discussion] Re: motion picture, registration, & |basicpinhole info | | |Ed: With humble gratitude to all on the list, I must confess I can't |imagine measuring a pinhole to the thousandths of an inch. You are right |that a Bolex with a pinhole would work wonderfully, too. I guess I was |hoping to bypass the need for a Bolex. I did build the camera. It |actually required that I buy a $1.50 needle and .79 of dowel rod, no more. |I had a shipping box, etc., lying around. Part of the charm for me is |making this film with as few resources as possible (and few indeed do I |have). My only experience with pinhole photography was one summer as a |child, an art class. I still remember setting the box down on a rock. |But to address the practical matters, you may be right about the |difference between pulling film around a dowel that is bare and pulling it |around a dowel with 50 ft of film on it. Perhaps I can just do a test of |the whole 100 ft and make whatever adjustment I discover is needed. But |also, suppose I have determined the f-stop I need. (Stop me if I should |just read a certain book everyone has.) How does this translate into |exposure time? I realize the f-stop is determined by the focal length and |the hole diameter. Suppose it is 2. Does that mean expose for 2 seconds? |My humble thanks. |Bernie | |
