Re: [APML] Precise alignment of a 500 mm lens and a guidescope

[Alan Voetsch <critter12952@yahoo.com>]

Hi Emmanule,

--- Matt BenDaniel <matt@starmatt.com> wrote:
> You'll want to be able to adjust the aim of the guide scope by at
> least a degree away from the center of the camera's FOV.  This will
>enable you to both compose your picture and choose a good guide star. 

> I prefer the over/under configuration for guiding.  Although it may
> also
> provide less opportunity for flexure, the main benefit (over side by
> side)
> is that it is much easier to balance in DEC.

> Does the guide scope have a movable primary (for focus)?  Do you have
> a reliable mirror lockdown?  If not, it may not be a good choice for 
>  a guide scope.

Matt has made excellent points. I'd like to reinforce what he said
about using a moveable mirror lens or scope as a guidescope. This
subject comes up often on MAPUG and the idea of using this type of
setup is usually not a sound one. Especially using this type of lens to
guide a SCT. If the mirror moves (and it will) your guiding will be
off.

Alan

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