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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
> > >
> > >