Sun viewing safety

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From: "Al"
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Subject: Sun viewing safety
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Date: Thu, 06 Nov 2003 02:34:36 GMT
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Organization: Optimum Online

A Not sure what you actually read, but if you use an aperture filter, such as
A a Baader, and if it's installed properly, it would be perfectly safe to view
A the sun. The key word here is "aperture" filter and not eyepiece filter.
A I've seen some ep filters which I believe are unsafe, as using it would heat
A your ota and cause damage.
A
A Just make certain that there are no holes in the Baader film. Finally, make
A certain that you also protect your finder scope with Baader film. If you
A don't have film for your finder scope, make certain that it's REMOVED from
A the scope before your viewing session.

Removing the finder is certainly a safe tactic as it prevents
accidently looing into it wuth no protection. This is probably a wise
thng for pulic viewing.
A less drastic method, for finders which are tough to remove or to
realign when put back, is to cap them. Then tape the cap on so it
doesn't blow off or be taken off by a visitor.
Actually I cap the finder for my solar viewing with masking tape.
Inevitably the Sun drifts out of the field (no tracking) and I have to
hunt it up again. Then I uncap the finder to project the Sun's image
on a card and center it. Recap the finder, look in the main scope.
Eye protection is a discipline that must be cultivted and
exercised for any one doing solar viewing.
When I worked at the Brooklyn Observatory in the 1960s *while in
school) and in the 1990s (for astronomy club use) we made sure the
frontend, aperture, filter was properly placed on the scope. The
instrument was a long refractor, whose objective was some 3 meters
off of the ground, too high to reach it to fix a loose filter. We also
inspected the filter, an old Microline model, for pinholes. These we
blacked out with dots of black ink.

---
þ RoseReader 2.52á P005004

Actually I cap the finder for my solar viewing with masking tape.
Inevitably the Sun drifts out of the field (no tracking) and I have to
hunt it up again.

I just minimize the size of the shadow of the scope on the ground, seems to
work and doesn't require keeping the finder on the scope.

jon