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(meteorobs) Video system compatibility
Video enthusiasts;
Compatibility issues between US and European video INTENSIFIERS should not
be a problem is my best guess. The intensifier I 've got runs off 12 VDC,
and the output of an intensifier is a light image, NOT an electronic
signal. The issue is how good an intensifier do you want. You can pay
$3000 for a scientific grade intensifier with LOW NOISE, good linearity
across the face, no dead pixels, better sensitivity into the near-IR. Mike
Palermiti in Florida is still of the opinion that the Russian made
intensifiers are just not that good (very noisy) if you want to push the
limiting magnitude of meteor detection. I do not know the specs of the
devices used in Europe. One problem with compatibilty is in the CCD camera
itself, since they use PAL video and we use NTSC standard video signals.
I have been interested in the quality of the European systems but have not
been able to examine their video output since I cannot read PAL format. My
personal opinion is that if you want to contribute to good science you
configure the best system you can with current technology. That may
translate into higher cost. The European's have put together a system for
less than $1000. Maybe they have found some good quality components that
we are not aware of in the US. Sirko, can you provide any info on this
thought?
There are other things to consider before you dive into buying a video
system. There is more to it than the intensifier (although that is the
heart of the system and the major cost hurdle).
1) You need a CCD at the back end, a low light sensitive frame rate CCD
camera is a few hundred bucks
2) You need to couple the intensifier to the CCD, Mike P. uses a f/1.1
transfer lens configuration, others fiber couple these which doesn't work
well under extreme temperature changes.
3) You need a front end lens, as low an f-stop as you can get ~$100-200
4) You need to record the video signal (are you gonna lug a VCR around in
the field that runs off AC) I did this with an automotive DC/AC converter
but I now use a 8mm camcorder that accepts external video inputs for
recording (far more portable and less power hungry). The other alternative
is to run a detection program directly on the video as its produced
real-time (need AC, computer and frame grabber board, (a few thousand) and
software for automated detection (which I am currently working on).
5) If you dont use a computer, you will have to play back the video on a TV
monitor (when the wife and kids will let you use them) and watch for that
short but beautiful meteor. I personally find this has far less appeal to
it than sitting out under the open sky and doing the same thing as a meteor
counter and plotter.
These are some of the things to consider in time and money if you decide to
do video observations.
Pete G.
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