Re: [APML] Focusing and temperature change issues during an exposure- advice wanted

["Steve..." <swalters@worldnet.att.net>]

Alan,

FWIW, I struggled for 2 or 3 years with a 12" Meade SCT and focusing. The
combination of mirror flop and (especially) thermal problems drove me to buy
an OTA with a carbon fiber tube. At one point, I had considered having a
carbon fiber tube made to replace the aluminum tube on my SCT but decided
that I also wanted better optics so I didn't go that route.

But you might consider rebuilding your SCT, it may be the cheapest way to
go. There are a couple of guys in Calif that make these tubes. This would
solve your thermal shift problem.

Steve...

----- Original Message -----
From: "Alan Voetsch" <critter12952@yahoo.com>
To: <astro-photo@seds.org>
Sent: Wednesday, November 13, 2002 7:33 PM
Subject: RE: [APML] Focusing and temperature change issues during an
exposure- advice wanted


> Hi Greg,
>
> --- Greg Hartke <ghartke@earthlink.net> wrote:
> > The Optec TCF (which means something like
> > "temperature compensated focuser")
> > is reputedly an excellent device.
>
> I know, I've heard of it on the SBIG list.
>
> > Dick Greiner was
> > involved in some
> > prototype testing of this device.
>
> Good, I need a hands on report on it.
>
> > Keep in mind it isn't cheap but it does the
> > job.
>
> I know, it's almost scary.
>
> Thanks,
> Alan
>
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