Exactly the way I've done it in the past. Just remember that most meteors will occur while you are rewinding and loading a new roll of film.
Tom C. ----- Original Message ----- From: "Peifer, William [OCDUS]" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: "'Skofteland, Christian'" <[EMAIL PROTECTED]> Sent: Friday, November 16, 2001 12:17 PM Subject: RE: Leonid meteor shower could be truly spectacular > Christian Skoftland wrote: > > What is the minimum exposure for 400 speed slide film at f2.8 that I > > should use to photograph the meteors? > > Hi Christian, > > An individual meteor is of short duration -- a fraction of a second to > perhaps a few seconds duration in the sky, depending on size of the > meteoritic particle, trajectory in the upper atmosphere, etc. Thus, no > matter how long your exposure time is, the light from any meteor will only > be present for a brief instant. (Kind of like very slow synch speeds in > flash photography.) Your minimum shutter speed should be at least as long > as the duration of an individual meteor. But catching a single meteor this > way is difficult. Chances are that by the time you figure your reaction > time and your shutter lag time, much of the light intensity from an > individual meteor would be gone. Thus, it's often recommended to go for > long exposures. The longer your exposure time, the greater your chances of > capturing a meteor on film. Also, the shorter your focal length, the more > of the sky you will image, and the greater your chances of capturing a > meteor on film. The only disadvantages to very long exposure times is that > (a) you will get star trails instead of nice sharp points, and (b) you will > get a washed out sky instead of a nice dark sky due to light pollution at > your observing site. With a 50mm lens and a fixed-tripod mount, you can > typically expose for as long as 20 or 30 seconds before star trailing > becomes noticeable. With a 28mm lens and fixed-tripod mount, you can go up > to about a minute. If you don't mind a little star-trailing, you may want > to just open the shutter and expose for a few minutes. If you're trying to > catch a single meteor on film, perhaps you could open the shutter with a > cable release, then close it when the first meteor flash appears. > > Hope this helps. > > Bill Peifer > Rochester, NY > - > This message is from the Pentax-Discuss Mail List. To unsubscribe, > go to http://www.pdml.net and follow the directions. Don't forget to > visit the Pentax Users' Gallery at http://pug.komkon.org . - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
