Re: [APML] SBIG STV-eFinder??????

[KGKIRKLEY@aol.com]

In a message dated 6/18/02 7:47:49 PM, westergren@netzero.net writes:

>Kent,
>
>I use my STV with E-finder lens regularly, and I wouldn't be without it.
>
>However I use it a bit differently than SBIG conceived of it.
>
>
>
>I have the SBIG E-finder lens mounted in a Delrin (plastic) holder that
>is
>
>permanently mounted next to my scopes (on an AP1200QMD).  The 1"f4 lens
>is
>
>focussed by sliding it and locking it with a nylon thumb screw, just like
>an
>
>eyepiece.  My original focus about 18 months ago is still good.  I put
>the
>
>STV into the delrin holder, aligning the STV body flat to the mount, and
>
>slide it all the way into the holder, held with another nylon thumb screw.
>
>I use this E-finder assembly as my finder and for aligning my scope FOV
>on
>
>my photo target.  For comets, I use this assembly for guiding on the head.
>
>
>
>I have tried guiding on stars with the E-finder, but it seems marginal.
> The
>
>errors I get with the off axis guider are much smaller than with the
>
>E-finder (corrected by the STV for focal length into arc-sec errors).
>
>
>
>The best feature I like about the E-finder is with my fixed mounting of
>the
>
>lens, I can put the STV in and out several times a night, without loosing
>
>the orientation and focus of the E-finder and the cross hair aim point
>of my
>
>scope.  This allows me to point the scope and identify star patterns with
>my
>
>reference sky charts next to the STV control display while looking at both
>
>with my reading glasses on.  I set the STV display to compensate for the
>
>telescope reversed image, so up on the STV is always North and it matches
>my
>
>charts.
>
>
>
>I have tried using the E-finder with the barrel screwed into the STV and
>the
>
>STV on a piggy-back ball camera mount.  Boy was that a futile exercise,
>
>trying to get it aligned with my scope.  There's no way to easily move
>the
>
>STV from that position and get it back again.  Since I use my STV as an
>off
>
>axis guider and as a prime focus camera on my scopes, the fixed mount I
>
>described above really works well.
>
>
>
>I may have answered more than you asked, but maybe it will help someone
>else
>
>too.
>
>Don
>
>
>
>For my deep sky photos, I move the STV to an off axis guider.

Don thanks,
What instrument are you guiding?
So you have found that using an OAG instead of the STV with eFinder works 
better??
Kent Kirkley

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