RE: Tesla Coil Photography
>Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
>Many thanks for all the fine and detailed information on how to setup a
>camera for Tesla coil photos. I had too slow of film, not enough aperture,
>and probably not enough exposure time. I will go to ASA 400 film at f1.4
>and run through a bunch of different timings form 1 sec to 16 seconds which
>should pin down my situation well.
ASA400 at f1.4 will be seriously overexposed. Also, the narrow depth of
field you'll get at f1.4 will make for blurry streamers going towards or
away from the camera. Since I do well with ASA200 at f2.8, you'll need an
even smaller aperture with ASA400.
>Apparently, if the room is dark, the exposure time only determines how many
>streamers are captured. The film speed and aperture really determine how
>bright the sparks are in the photo. Thus, you can get a few streamers or
>many depending on how long the exposure is. I never realized this
>Since I am a bit far away from the coil (15-20 feet) I will go for larger
>apertures to be SURE something gets captured.
Surprisingly, the camera-to-subject distance plays NO part in exposure
calculations. You'll be disappointed with overexposed shots if you try to
factor distance in.
>The exact streamer
>brightness and distance play into all this too, so some trial and error is
>still needed. However I will now be pretty close to begin with.
>I'll switch to my older Minolta XE-1 which has double exposure capability,
>longer preset exposure times, is made of solid metal, and is "expendable"
>:-) It has a minor light metering problem but that does not mater in this
>Many many thanks for all the help!
Regards, Gary Lau
Waltham, MA USA