From: "William Cook" 
To: atm{at}shore.net
Reply-To: "William Cook" 


Frank wrote:

>>>Why hasn't this variant of the Maksutov (sub-aperture Maks) been more
>>>popular? . . . why can't you make a Mak-cass the same
way, with the corrector in front of the secondary?<<<

By not correcting aberrations at the aperture, you are missing your best
opportunity. Let’s suppose you were assigned to take a pile of
stones—-granite, jade, coal, pyrite, and marble—-and sort them into 5
baskets. If each stone was the size of a baseball, the project would take
you, perhaps, an hour.

Now then, keeping everything else the same, let’s reduce the size of the
stones to that of peas. Now, how long will it take and how much harder will
it be!? And, was that piece granite or marble?

Though stones and optics don’t seem to have much in common, the analogy
will get your thinking on the right track.

Over the years, Australian, Ralph Field, has designed many sub-aperture
Maks. I do not think he has been totally satisfied with any. Frankly, I
love the idea and hope one day to have enough time to tinker with designing
one or two myself. Methinks one more element will be required to thoroughly
correct coma.

Just a thought.

Kindest Regards,

Bill Cook






_________________________________________________________________
MSN 8 with e-mail virus protection service: 2 months FREE*
http://join.msn.com/?page=features/virus

--- BBBS/NT v4.00 MP