'tis my understanding that (unless you have a quartz lens) the optical glass
of a standard photographic lens will block most UV light.
--
Piers
-----Original Message-----
From: olympus-owner@xxxxxxxxxx [mailto:olympus-owner@xxxxxxxxxx] On Behalf
Of Marten Beels
Sent: 18 September 2007 15:12
To: olympus@xxxxxxxxxx
Subject: [OM] Re: [OT] lighting detector
> Marten Beels <mbeels@xxxxxxxxx> wrote:
>
>
> I started reading a bit about lightning spectroscopy, and a few
sources
> indicated that lightning was a strong source of UV light, around 400
> nm.
I'm not surprised that a lightning strike would emit a fair amount of UV
(+visible+IR+radio) as it's much like an electronic flash (different gas
composition though) not in a tube. Did you find any images made from
lightning in the UV range ?
...Wayne
Wayne Harridge
http://lrh.structuregraphs.com
I didn't find any UV images of lightning, but I did find some interesting
reading on lightning spectroscopy. What I was really wondering is what sort
of "precursors" there might be. What sort of events (if any) happen before
the visible flash? What is the first indicator that lightning is about to
strike?
If each re-strike of a lightning bolt are separated by approximately
40-50ms, and a camera has a delay of 130-160 ms, then there need to be
several re-strikes in order to catch one on film.
I did read that lightning typically has strong characteristic lines in its
spectrum due to N2 and H2, and that certain types of lightning, like the
"dart leader" has a slightly different signature of spectral emissions.
Lots of fascinating reading on lightning,
Marten
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