Re: Safe distance for photographing operating tesla coils with digital cameras?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

Hi Garry,

On 2 Aug 2005, at 13:29, Tesla list wrote:

> Original poster: "Garry Freemyer" <garryfre@xxxxxxxxxxx>
>
> Recently, I posted a url to my website that has some pictures of my
> tesla coil in the photography Usenet group and the subject came up
> about the main picture here ....
>
> http://home.pacbell.net/garryfre/
>
> and what is the minimum "safe" distance one should be from a tesla
> coil when taking a picture, given the output power or voltage of the
> coil before it starts messing with the camera.
>
> Someone replied that by publishing this picture, I was risking the ire
> of the entire tesla coiling community. They said "You are publishing a
> false representation of what you actually saw when taking the
> pictures. What would happen to your credibility with them?"
>
> I asked him to elaborate on exactly what mis-representation he was
> talking about but he didn't reply. All I can guess is that he was
> taking exception to the publishing of the picture with artifacts that
> might have been due to EMF or maybe dust floating in the air, but he
> was quite serious and sounded angry. I am amazed how many crackpots
> are in that forum. Still it was only a guess that he was having a cow
> over some elite standard he had set called "Photo-Purity" and that
> artifacts constitute lies and that everyone should hold to this
> standard. Does anyone have any other clue what this hoser was talking
> about?

He would be talking about the time exposure I think. Seeing a still
picture with sparks leaping from the coil in all directions
apparently at once. This guy seems to overlook that there is an
artistic side to this business :)

> I remember, that all my pictures from the Northern California
> Teslathon were ruined because I was too close and didn't know it. I
> had one picture, on the digital stick where the foreground was a
> wonderful picture of streamers from a coil at San Francisco, but was
> ruined by a clear image of my living room curtain from my apartment
> some 300 miles north. Bleah!
>
> So the question still remains. What would be the minimum distance for
> coils. Does anyone have any guidelines that might be a clue? With my
> small coil capable of 5 foot streamers, I kept a minimum of 30 feet
> away, and if I had to be fifty feet away, I'd have to sell my left leg
> for a telephoto lens, but I think it would not hurt to ask. Someone
> else might know via the lesson of hard experience, so that I don't
> have to. I find myself cringing at the idea of getting close to this
> coil I have, but how close is too close is something I have no real
> idea.

I photographed one of my coils throwing 5'+ in all directions one
night. To get all streamers and arcs in the frame I positioned the
(standard film) camera about 12' away. And yep - they were time
exposures :)

Malcolm

>