Posts Made By: Charles Teague

There is a substantial $100 difference between the Orion Ultra-Block and the Lumicon UHC in the 2-inch size. Is there a corresponding difference in the quality or performance of the two?

Charlie

In 1986 I bought a Chicago Optical RFT newtonian. I gave the scope to my son who now wishes to buy a new scope. I will buy the old Chicago Optical scope from him to boost his fund for the new one.

The spec plate has fallen off over the years, and I cannot remember the exact optical parameters. I have searched the Internet and haven't been able to find a listing for Chicago Optical. Maybe they are no longer in business.

Perhaps someone would share this information with me. The aperture was about 4.5 inches, the focal length was about 480-mm, which yields f/4.2. With the supplied 25- or 26-mm Kellner eyepiece, the magnification of 18x to 19x sounds about right, as I recall. But my memory is hazy, and I am not sure of these numbers.

I would also be interested in ideas one might have in improving the scope's performance, specifically to diminish the coma. Aside from the pricey ParaCorr, are there any suggestions?

I seek, also, suggestions about eyepieces for this little beast.