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Re: Getting good digital photos



Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 

My fault.  We usually use ISO 100 for best color saturation (light x time
factor).

Again, the straight vertical ground rod is very helpful in getting good
spark photographs even on small coils.

We also use a fireproof blanket to cover the oscillator base facing the
camera (approx 180 degrees).

Dr. Resonance

 >
 > Actually, it the settings depend on lots of things.  What Dr. Resonance
 > doesn't tell you is the film speed which is just as important as the
 > exposure length and aperature
 > as well.  Also, what works for a large coil with bright, thick streamers,
 > usually doesn't work well for smaller coils with purple streamers.
 >
 > For mid-size coils (about 2kW to 3.5kW), I find that a f/2.8, 1 or 2
second
 > exposure looks best using ISO 800 film speed.
 > The photo below is shot at f/2.8 for 2 seconds using ISO 800 on a Canon
 > Digital camera.  The picture came out quite well, although it had to be
 > adjusted in Photoshop
 > to make it a bit brighter (levels adjustment) and also converted to black
 > and white (channel mixer)
 > http://www.spacecatlighting-dot-com/teslabw_gallery/bigimages/teslabw01.jpg
 >
 > Its also important to realize that low power coils are the most difficult
of
 > coils to capture photographically.  This is because the streamers are
 > typically purple and much less
 > bright then higher power coils streamers.  Also, most lens glass
attenuates
 > light at the purple to UV portion of the spectrum quite readily which adds
 > to the difficulty.
 >
 > Dan
 >
 >
 >
 >
 >  > We use a tripod with timer delay on the camera at 4 sec. exposure at
f2.8.
 >  >
 >  > It also helps if you have a straight vertical ground rod --- the sparks
 >  > "climbs" due to the heating of the air and produces very exciting spark
 >  > photographs --- the sparks look thicker than in reality.
 >  >
 >  > Dr. Resonance
 >  >
 >  > Resonance Research Corporation
 >  > E11870 Shadylane Rd.
 >  > Baraboo   WI   53913
 >  >
 >  >  >
 >  >  > Some of you will have noticed, as I have, that many Tesla coil shots
on
 >  > the
 >  >  > web are blurred, out of focus or are just don't convey the size of
the
 >  >  > sparks/streamers.
 >  >  >
 >  >  > May I give a list of suggested criteria that I use for digital
cameras
 > (I
 >  >  > did win an award for my cover shot on my site - well a small one
 > anyway)
 >  >  >
 >  >  > - Always use a tripod (or stack of bricks or the previous model TC).
 > For
 >  >  > medium exposures of seconds a hand held camera will blur a lot. The
 > sparks
 >  >  > will be sharp but the rest will be blurred.
 >  >  > - Make sure you get the end points of all the sparks to either side.
 >  >  > Chopped off sparks don't really give the impression of size. (that
is
 >  >  > unless you do a Richard Hull and have sparks ONTO the camera)
 >  >  > - Try to get the sparks at a right angle to the camera by using a
 > breakout
 >  >  > point or grounded object.  Only by doing this will you see the full
 > spark
 >  >  > length in comparison with a fixed measure (which is usually the
 > secondary
 >  >  > winding height).
 >  >  > - Have a person in the background for scale (at a safe distance).
Even
 >  >  > Tesla himself got this right in his photos (admittedly with double
 >  > exposures).
 >  >  > - Adjust the background lighting to be able to see the surroundings
for
 >  >  > scale. It is best to at least partially cover the spark gap as this
 > tends
 >  >  > to wash everything out.  It should have a shrapnel and UV guard on
 > anyway
 >  >  > shouldn't it?
 >  >  > - Fix the focus on the TC toroid with lights on, hold the focus,
then
 >  >  > lights off, sparks on and shoot. This is needed as you can't
autofocus
 > in
 >  >  > the dark. You may need to grow extra hands for this.
 >  >  > - Let the camera do an auto exposure and it will finish when it has
 > enough
 >  >  > light (may be 10 seconds on my camera).
 >  >  > - Don't put a large number of shots on your site. You choose the
best
 >  >  > one(s) to save others the trouble of downloading many.
 >  >  > - I use thumbnails linking to a largish size of compressed photo of
 > 200 -
 >  >  > 400k but I am very choosy with the photos and lots get discarded.  I
 > keep
 >  >  > the resolution full (4 megapixel before cropping) but reduce the
colour
 >  >  > spectrum from 24 bit to 16 bit to save space. I can't tell the
 > difference.
 >  >  > - I use some RF protection if my camera close up to the coil with a
 > metal
 >  >  > can made for the purpose.  I have previously used aluminium foil to
 > wrap
 >  >  > the camera with lens sticking out.
 >  >  > - Avoid windy times (unless you want to show the banjo effect) as it
 > makes
 >  >  > the streamers look blurred.
 >  >  > - (I might add if in Australia, don't hold your baby up in front of
the
 > TC
 >  >  > for publicity shots).
 >  >  >
 >  >  > Any suggestions welcome particularly about using film cameras.
 >  >  >
 >  >  > Cheers
 >  >  > Peter (Tesla Downunder)
 >  >  >
 > <http://members.iinet-dot-net.au/~pterren>http://members.iinet-dot-net.au/~pterren
 >  >  >
 >  >  >