Re: [APML] 8" Reflector decent enough for prime focus AP?

["T&JDiana" <tomdiana@acegroup.cc>]

Rex,

Not to completely discourage you, but I'm afraid that you will discover that
there is no such thing as "extremely simple prime focus photography."  It is
a very challenging undertaking, one that should be eased into.  If you
decide to get into prime focus photography, you would need a dual-axis drive
with a hand controller, a polar alignment scope, a separate guide scope (or
off-axis guider) with an illuminated reticle eyepiece, a means of accurately
focusing your camera (e.g., a bright  focusing screen and magnifier, a
knife-edge focuser), etc.  Speaking of focus, you raise an important
question as to whether the scope you are looking at can achieve focus with a
35mm camera body.  Even if it could, a 1.25" rack-and-pinion focuser would
present some problems.  You may not be able to lock it in place.  There
would also be some vignetting.

Bearing all of this in mind (and assuming that you haven't given up all hope
of pursuing this hobby), I'd suggest starting out with some piggyback shots
or maybe some eyepiece projection photography.  You would not have to own
quite as elaborate or a system.  Check out Michael Covington's book entitled
Astrophotography for the Amateur for some valuable information on these
techniques (http://www.covingtoninnovations.com/astro/).

Tom

----- Original Message -----
From: "Rex Moore" <RMoore@fool.com>
To: <astro-photo@seds.org>
Sent: Monday, March 11, 2002 10:20 PM
Subject: [APML] 8" Reflector decent enough for prime focus AP?


> The introductory email said all levels of experience are welcome, so I
hope
> you don't mind a question from a rank beginner!
>
> This Orion SkyView Deluxe 8 EQ Newtonian is about at the limit of what I
can
> afford to purchase right now:
>
http://www.telescope.com/cgi-bin/OrionTel.storefront/3c8d7c3a03724cb02719c0a
> 80a6506d5/Product/View/A319
>
> I'd go for a less-expensive Dob mount, but I'd like to do *some*
> astrophotography, if for nothing more than to have a visual catalog of
> different things I've viewed. Nothing fancy... just some extremely simple
> prime focus photograhpy. I've read enough to where I know not to expect
> miracles, but before I make the purchase I'd just like to know from the
good
> folks on this list if this scope will allow some basic photography at all,
> or will I be in for a major disappointment. (By the way, I'd purchase the
> electronic drive, and I have a decent enough camera body for the job).
>
> Sorry for the simple question, but this will be my first scope purchase
and
> some things I've read have caused me to wonder (like the actual focusing
> point of some Newtonians do not extend outward enough to reach the
camera's
> film plane).
>
> Thanks,
>
> Rex
>
>
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