Two thoughts from yesterday's digest
1) Anyone ever consider how lucky we are to have someone like John Hermanson
participating on this list? When has he ever refrained from suggesting a
repair that was appropriate for the person posting?
2) No one should ever consider solar observation through any type of filter
without first:
- making absolutely sure it's a 5.0 D or higher *at all wavelengths* from
far IR to far UV
- checking it for any defects
Many filters block the visible spectrum, but UV and IR are what fry your
eye. That's why multiple layers of overexposed color film don't work.
Destructive testing is certainly inappropriate. Buy from trusted sources and
check for pinholes; they can let in enough UV/IR to damage your eyesight. If
you find them, use a heavily pigmented opaquing fluid to cover them. I have
a solar filter for a small telescope and the inside of my filter is covered
with little white bumps, and I add several more every time I see a hole (I
miss a lot).
While totality might be safe, I'd be real careful about trying to catch the
Diamond Ring with the naked eye. Photography is another story. If you
destroy a camera or lens, it's cheap and easily replaced compared with
what's behind the finder.
Frank
------------------------------
Date: Wed, 7 Jul 1999 17:18:38 -0400
From: "John Hermanson" <omtech@xxxxxxxxx>
Subject: Re: [OM] blocked shutter - HEL*P!!!
If the mirror does not come down with red B/60, then it is most likely a
mechanical problem.
John
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Camtech / Olympus Service since 1977
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516-424-2121
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and
------------------------------
Date: Wed, 7 Jul 1999 23:34:11 +0200
From: "Thomas Haegin" <haegint@xxxxxxxx>
Subject: Re: [OM] Total eclipse & Sunfilters?
Olaf,
this shop in Germany has all the right filters. The site is in German,
though:
http://www.intercon-spacetec.com/
I ordered an ICS filter there yesterday. Some days ago, John Petrush (sp?)
and Richard... from England had good postings about eclipse shooting.
greetings,
Thomas
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