Video, frames and fields was Re: Hybrid-Maggy

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

Original poster: "Robert Jones" <alwynj48-at-earthlink-dot-net> 



 > Original poster: Harvey Norris <harvich-at-yahoo-dot-com>
 >
 >
 > --- Tesla list <tesla-at-pupman-dot-com> wrote:
 >  > Original poster: Bart Anderson
 >> primary and secondary arcing are separate in time)
 > Tapings of Mark Metlicas large coil showed that frame
 > per frame,many empty periods of non arcing exist,
 > which seem feasible for a very low natural res
 > frequency of long wire length. >

This probably  has nothing to do with the frequency of the secondary if
that's what you mean.  It is usually caused by beating or aliasing of the
video frequency with the break rate of the coil. The video exposure time can
be much smaller than a frame period so if the break rate of the coil  is
close to the frame rate or some integer of the rate and the only source of
light is the coil you can have an almost blank video except for the bleed
thru ( an effect caused the no zero sensativity out side the field exposure
time. This is particularly noticeable on auto exposure and gain. The is also
a bleed over effect to adjacent pixels particularly during saturation this
may account for fuzziness of some pics).  You can get a similar problem with
digital still cameras.  When I first got blank pics from my still dig-camera
I  assumed the RF field had disrupted its operation. The moral of that is
set the exposure time to at least one break period.

I assume coil to video synchronization and the correct phasing via a
triggered gap would solve this problem. or a sufficiently high break rate to
ensure one discharge per frame exposure. Irritatingly as you suggest there
is also the interlace problem i.e. most video cameras build a frame from two
fields so it not possible to get a full frame picture (high res) of  a
single discharge.

I wonder how high resolution still dig-cameras create their frames in video
mode i.e. from two consecutive exposures or from one?? This may be
irrelevant as the compression required to store a significant number of
frames in the storage media may produces poor quality images

How did KVA get round the video problem or if they had the problem?
Synchronization, 240 break rate or just maximum exposure time?

Has any one tried to observe streamer growth by examining a video field to
field?

Bob