Re: Getting good digital photos

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Chris Roberts <quezacotl_14000000000000-at-yahoo-dot-com> 

My favorite way to take tesla photos is to "paint" the coil with a 
flashlight. While the camera is taking the picture, the coil is illuminated 
with a flashlight. Most of the time, it's necessary to move the beam all 
around the coil during the exposure to ensure that the coil is lit evenly. 
Doing this, the coil is well lit while the sparks remain against a dark 
background, letting them show up better. Also, by having the light on the 
coil before the picture, you can let the camera focus itself with the 
lights out. Here are a couple of pictures showing both of my coils lit like 
this.
Mini coil: 
<http://hot-streamer-dot-com/temp/mini_1.jpg>http://hot-streamer-dot-com/temp/mini_1.jpg
6" coil: (Large picture) 
<http://hot-streamer-dot-com/temp/1080VAmed.JPG>http://hot-streamer-dot-com/temp/1080VAmed.JPG
6" coil: (Same picture, but smaller) 
<http://hot-streamer-dot-com/temp/1080VAsm.jpg>http://hot-streamer-dot-com/temp/1080VAsm.jpg
The mini coil was lit using a standard 3D cell flashlight, which gave a 
warmer yellowish tint to the picture. The large coil was lit using a fancy 
lithium battery powered light, which produces a very white and crisp beam. 
It lets the blue color from the spark and saftey gaps to show up more, and 
gives a sharper look to the coil.
So has anybody else ever played around with this technique? If so, I would 
like to see how it turned out.

Tesla list <tesla-at-pupman-dot-com> wrote:
Original poster: "Peter Terren"

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







-Chris