"D. Couillard" wrote in message news:GgY2d.22947$yW6.9263@clgrps12...

I know that there are practical upper limits for magnification for a given
scope, but is there also a practical lower limit to magnification? I built a
10" F5 truss tube dob and used a 1.25" focuser on it. My lowest power
eyepiece currently is a 32mm Plossl (40X). So, how low can I go, and would
there be advantages other than FOV to lower power with my setup?

Yes, you can go lower than that using a 40mm Plossl. However, there is
no benefit to doing so, because you have already achieved the maximum
field of view possible with your scope when using a 1.25-inch eyepiece.
There's a lucid discussion of this in the October issue of Sky & Telescope,
and it has also been hashed over innumerable times on s.a.a. Try a
Google search.

BTW my highest power eyepiece is a 13mm Nagler (97X) and I carry a 2X
Barlow.

Going lower is one thing, but you can *certainly* go higher than that --
much higher! In fact, I would go so far as to say that you are wasting
a large part of the capability of your scope by sticking at such low
powers. Your current max of 194X is fine for deep-sky viewing, but you
should get *much* better images of the planets at 250X or 300X on a
steady night.

- Tony Flanders