Re: [APML] Medium format cameras and films, along with Tak scopes

["westergren" <westergren@netzero.net>]

Alan,

 The extender Q is a limited (1.6x) barlow for 1-1/4 inch eyepieces.  You
can't plan to use it for photography.  The Petzval design has a couple of
lenses just in front of the focuser, so conventional long barlows can not be
used.  You can use the Televue Powermates, which are not barlows.  Think of
the petzval rear elements as being great field flatteners that can not be
removed from the scope.  The FSQ gives sharp images across a wide area
(about 88mm across) but does have some illumination fall-off toward the
edges.  I really like my FSQ, but it would be even better without the
vignetting.

To use the FSQ for AP, you will need expensive TAK adapters, or machine your
own.  I made my own OAG that screws directly into the FSQ.  BTW, the FSQ has
a great built-in camera rotator, that has no focus shift, but allows
composing a shot just the way you want, or finding an elusive guide star
with the OAG.

Don

> I have another question: Does the 'Extender Q' help the hot spot
> problem with the 106?
>
> Thank you both for the excellent answers and tons of info.
>
> Alan


_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo