RE: [TCML] "Phantom Streamer" Photographs

["Lau, Gary" <Gary.Lau@xxxxxx>]

Hi Jeff,

Foremost, I agree with Terry, in that what really counts is how pretty the picture is, and yours are very!

I believe what you are seeing is what I had referred to as a stable streamer - see 3rd from last image on http://www.laushaus.com/tesla/minicoil.htm.  I've only witnessed these on lower powered coils.  Text from my web page:
"Above shows something that I rarely see on other coils.  When there is a grounded target just out of striking distance, the usually chaotic streamer(s) will occasionally coalesce into a single, sinuous, un-branching, slowly writhing streamer, lasting 1-5 seconds at most.  The sound generated is more stable and louder than normal as well.  In the photo, there is a basement lally column 10" away from the toroid, and there will be a brief strike to it every 30 seconds or so."

The fact that these stable streamers move more slowly than the normal chaotic streamers will naturally make them appear brighter and more evident in a photo.

Regards, Gary Lau
MA, USA

> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf Of piranha
> Sent: Thursday, May 22, 2008 2:42 AM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] "Phantom Streamer" Photographs
>
> Hi Jeff,
>
> Pretty normal...
>
> The long exposure time "smears" things a bit.  The camera has some "hot
> pixels" (modern cameras "subtract" them, but they don't "linearly
> account" for them.  So they show up under "brightness" where they
> disappear under "simple dark")...  But the corona and leaders are very
> well known.
>
> The current in them is super dependent on space charge capacitance
> depending on the shape and size of the terminal and the voltage and
> frequency as well as the exact driving voltage waveform.  Higher
> frequencies have higher currents in this case, and so it goes...
>
> The direction matters since a leader going right towards the camera lens
> will be much brighter.  All the brightness at zero degrees rather than
> 90 degrees....
>
> Be a bit careful since digital cameras worked to the ends of their
> capabilities can do very odd "ghosting" things...  They seems to be
> happily immune to local HV fields now days though :)
>
> What really counts, is how pretty of a picture you can get out of it all :D
>
> Terry
>
>
>
>
> and
> Jeff Behary wrote:
> > Hey All,
> >
> > A friend of mine Cip just got a digital camera much better than mine.  He can
> attach lenses and do exposures more than 1 second.  I told him of my ordeal with
> capturing "Phantom Streamers" in photos and he decided to give it a shot.  The
> results are interesting...
> > http://www.electrotherapymuseum.com/2008/CipPhantom2/index.htm
> > The violet light surrounding the brush discharge indicates the roots or nearer
> portions of the Phantoms.
> > With 4 second exposures, they started to appear.  Their constant movement and
> lack of light results in a consistent blur that in the photo extends , but this is all  I
> can manage at the moment with the camera and the settings I'm familiar with.
> >
> > The "Phantom Streams" are strange faint discharges that extend perpendicular
> from the electrode/top load.  They can change appearance by changing the
> frequency of the coil, becoming straight lines that strobe inward and outward, or
> take on the appearance of faint static electric discharges, plume-like or slightly
> branching.  With low voltage tank circuits (~500V - 2kV) they seem to appear best
> when large caps are used (1/2 - 1 mfd) and intermittent spark gaps (opened to the
> point where they start to sputter or become irregular).  With higher voltage tank
> circuits (10 - 30kV) they seem to appear best when very little current is used (30mA
> or less) and a spark gap rather close (set to fire at only a few thousand volts).
> >
> > In the case of a few of my Pancakes, I can get them to appear from 8 - 12" or
> more using a 9" flat spiral of magnet wire heavily insulated in wax.  I've been able
> to also produce them in cylindrical Tesla Coils, normally those physically large
> compared to the tank circuit's capacity.  In large coils they can appear an inch or
> more in diameter, for most 8 - 10" Pancakes they appear as luminous threads 1/16"
> - 1/8" in diameter or more.
> >
> > http://www.electrotherapymuseum.com/2008/CyclonePlus3/index.htm
> > To show some unusual proof of their existance, I grounded myself to one end of a
> series spark gap and approached the other end to the region of air containing the
> "Phantoms".  The result was a consistent firing of the gap, the total section length
> going from 1 1/4" - 2" or more.
> > http://www.electrotherapymuseum.com/2008/CipPhantom/index.htm
> > In another batch of photos, they appear as a sort of halo around the brush
> discharge.  The actual discharges are about twice the length of the halos that got
> captured.  One photo, slightly blurry in appearance, is actually a 30 second
> exposure!
> >
> > Complete blueprints for a simple machine to make "Phantom Streamers" are
> currently being drawn.
> > Jeff Behary

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