Re: ATM Planetary scope idea

["Bob May" <bobmay@nethere.com>]

The biggest thing you want with the planetary scope is focal length.  The
longer, the better.  This gives the ability to get the higher powers of 400
and more without having to go to very short FL EPs.  The aperture, of
course, should also be able to support these magnifications or you will be
seeing more like just a bunch of fuzz.
I was amazed when I looked at Mercury for the first time with my 200"
refractor as the planet actually had real cusps on the ends of the image of
the planet.  I could actually see the planet as a planet like you see the
moon.  The image was small because the 133x that I was using was about the
limit of the EP that I had but still, the planet definetly looked like it
was that rather than a blob with fuzzy edges like I've always seen in the
typical short FL Dobs and other scopes.  16' of FL does make a difference!
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net