RE: [APML] 5.5" Schmidt Woes

["John C. Mirtle" <mirtle.j@home.com>]

Thanks Robert, Bobby and Dave;
	As the 5" Schmidt isn't equipped with a filtered film holder, so I will
follow up the lead for Newport Glass. First, I want to get it collimated. It
is unfortunate that no-one has filled the gap left by Epoch. I'm sure that
my Schmidt isn't the only one around that needs tweaking. I also know Peter
from when he lived in Alberta in the '80's and I agree with Dave - this
isn't the thing to catch his attention.
	Dave - Celestron's Schmidts are actually very adjustable. Too adjustable
for my liking. You can change the centering of the corrector plate. (Just a
few millimeters) The film holder is also adjustable for centering. This
appears to be a weak point in their design. On both my 8" and 5" Schmidts,
these centering screws have been loose. I would recommend that anyone with
the Celestron design epoxy these grub screws in to place, before they work
loose and you lose collimation. The film holder distance to the primary can
be adjusted for focus, but only by someone braver than me. Finally, there
are 3 collimating screws on the primary. I guess it's time to get the
wrenches out, or I will never catch up with Loke..... Thanks guys!

John Mirtle
Calgary, Ab. Canada

-----Original Message-----
From: owner-astro-photo@seds.org [mailto:owner-astro-photo@seds.org]On
Behalf Of Bobby Middleton
Sent: Sunday, September 30, 2001 7:45 PM
To: astro-photo@seds.org
Subject: Re: [APML] 5.5" Schmidt Woes


---- Original Message ----- > And finally - has anyone stumbled across a
5.5"
> > Hydrogen-alpha filter, W92 or W25? Thanks!
>

Browse here John to see if they have something close.
http://www.newportglass.com/schott.htm
Bobby Middleton



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