Archived posting to the Leica Users Group, 2002/02/17
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]That's correct that sound speed should be 24fps in the US. Often the shutter was designed to be open for more than 180 degrees so you could have a longer shutter speed than 1/48. Of course one on-off cycle is 1/24 but there is no guarantee that it is running on-speed. Still even then if you shoot at 1/30 there is no way to tell if a given frame is timed with more or less of the open part of the cycle. Mike D - ----- Original Message ----- From: "Bernard Cousineau" <flatbroke@sympatico.ca> To: <leica-users@mejac.palo-alto.ca.us> Sent: Sunday, February 17, 2002 5:58 PM Subject: Re: [Leica] OT: 16mm projector shutter speed > > i have an old 16mm projector that i got at a thrift store. i plan to > > try using it to light some nudes--i'm going to try projecting a movie > > onto my model. i'm windering how to be sure i get the right amount of > > exposure, since my light source will be flickering. i'm *thinking* the > > shutter speed on a movie projector is 30 fps. if that's correct, then > > i'm thinking shooting at 1/30 will guarantee me getting only one > > illumination per frame. is that right? > Brad, > > Your projector should run pretty close to 24 fps, but many projectors will show each frame twice to minimize the apparent flicker. This means that each frame will be on screen for either slightly less than 1/48th or 1/24th. On top of this, some > projectors have been modified to run at 30 fps, showing each frame only once. The purpose of this is to facilitate cheap video transfers. If you are in a country where video runs at 25fps, your projector may have been modified to run at that speed. > What I suggest is to run a test first at speeds between 1/8th and 1/60th and see what works best. > The easy way out, of course, is to dupe the frames that you want and use a slide projector. > > Bernard > -- > To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html > - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html