High speed arc photos: rotating mirror vs streak camera

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Scott Hanson" <huil888@xxxxxxxxxxxx>

Just to stimulate further discussion & experimentation, there are at 
least two techniques that can be used to separate and record the 
multiple discharges that make up a tesla coil streamer.

In the first technique, the moving image is swept across a fixed 
detector. This can be accomplished by using a rotating mirror, etc, 
to sweep the image across photographic film or a CCD detector. This 
is the technique being used by Peter and Terry.

In the second technique, a fixed image is projected onto a moving 
detector, the "detector" usually being photographic film. This is the 
classic technique used in some types of high speed motion picture 
cameras, where a length of film is "accordian-folded" into a 
canister, then rapidly accellerated to a high linear speed just 
milliseconds before the "event" is triggered.

Do a web search for "streak camera" and you'll find info on many 
different implementations of streak cameras, some specifically for 
capturing high-speed events. Some clever modifications have been made 
to motor-drive 35mm cameras to convert them to streak-camera 
function. A 35mm camera will allow the use of specialized high-speed 
(high-sensitivity) films, but of course requires processing before 
the results can be viewed.

Also, Cameron mentioned the Electric Spacecraft Journal as a source 
of info on Harry Goldman's implementation of Tesla's spinning egg. 
Check out the back issues section 
(<http://www.electricspacecraft.com/bissues.htm>http://www.electricspacecraft.com/bissues.htm); 
the cover of issue #32 shows what appear to be high-quality 
streak-camera images of an electrical arc, presumably "amateur-made". 
There's no way to see anything but a tiny thumbnail image of the 
cover photo, so I've ordered a copy just to see what's actually 
there. The topics list for this issue makes no mention of any 
high-speed imaging content.

Regards,
Scott Hanson