Re: Colored sparks (photography)

From: 	Gary Lau  14-Dec-1997 1948[SMTP:lau-at-hdecad.ENET.dec-dot-com]
Sent: 	Sunday, December 14, 1997 6:35 PM
To: 	tesla-at-pupman-dot-com
Subject: 	Re: Colored sparks (photography)

I shot a roll of film on my coil.  While most of the shots were the
normal time exposures of the sparks, I was especially anxious to see
photos of the brilliant yellow sparks I had produced with table salt.
Upon getting the prints back, the normal shots came out super, but I was
utterly disappointed in the yellow spark shots.  The arcs were all
properly exposed, but their color showed absolutely nothing different
from the normal sparks.  It's like I was photographing ghosts!  How could
visual and photographic perception be so different?

FWIW, I was using ASA200 Kodacolor print film, between /f2.0 and /f2.8.
Between 5-8 second exposure times produced some real nice shots.

Gary Lau
Waltham, MA USA