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RE: Decent Pics.........

All of the spark pictures on my web site
http://people.ne.mediaone-dot-net/lau/tesla/tesla.htm were taken on 200 speed
film with an aperture of f/2.8.  3200 speed seems unnecessarilly fast.  A
tripod is mandatory!!!  And a shutter release cable is a great help.  Take
time to frame your pictures and lock the settings in the tripod before you
shoot.  Don't try to aim, focus, or compose while the coil is running.

My exposure times are typically 1-5 seconds.  Yes, this yields photos that
suggest that there are more simultaneous streamers that there really are.
But it also yields photos that are rich in sparks, the stuff we so long to
see.  You be the judge.

One further consequence of long exposure times is that exposure of
non-arcing surfaces is increased.  Thus, the photo must be taken in a
reasonably dark environment, otherwise a small amount of background light
will make everything overexposed and possibly tungsten-shifted.

If I may air a personal beef I have with many of the photos I see on web
sites:  Don't just show the sparks.  The sparks (IMHO) need to be seen in
the context of the rest of the coil.  Show the whole thing.  The spark gap
will provide enough light over a multi-second exposure to properly expose
the rest of the coil, particularly if the shot is taken indoors with plenty
of reflected light off the walls and ceiling from the gap.  Don't be afraid
to show the gap, even if it is overexposed.

>From a purely artistic perspective, I think it's nice if the arcs are
somewhat symetrical about the toroid.  This means that a single breakout
point will yield an asymetrical display, even if it is your longest spark.
Placing two breakout points to go left and right or up-left and up-right
will make a nicer looking photo.  Or no breakout points if your toroid will
break out randomly and evenly all around.

If the coil is not in the 5 foot+ arc league, the image will be helped if a
dark blanket or sheet is hung as a backdrop.  This helps with the contrast
of modest-powered arcs and also eliminates background clutter.

Gary Lau
Waltham, MA USA