Hi ! I have a cassegrainian miror kit but I don't know the negative focal lenght of the secondary convex mirror. Someone have a method to find it? Thanks...

Anyway, I wonder what you all think about the above scopes in comparison to the Pronto - is there enough of a performance boost to make an net expense of...

I order a Barlow today. This should ensure the clouds don't clear over MD, for at least another week or two. I am hoping that in the mean time, the skies clear...

Apogee has the 25x100's for $249.

Is it possible to take decent short exposure pictures (15 seconds) of double stars and bright star clusters with a scope on an EQ-1 mount and clock drive? ...

ICan you post your raw avi files of mars (or anything astronomical, for that matter) to alt.binaries.astronomy so we can: 1.) Watch them. 2.) Use them to...

Mirfak wrote: Would someone tell me which of these is correct? ADJECTIVE: Here are the transit times for . VERB: will transit at 23:00. NOUN: Is ...

Hi, About a month ago, I asked what to do with the concrete floor in my roll-off observatory. After about ten years of service, the floor paint was looking...

"Stephen Paul" wrote in message ... Given an SCT has a 33% obstruction that will have some...

By now. I am somewhat familiar with the concept & principles in Spherochromatism, but not so sure of the terminology used by the opticians to convey what they...

Someone called Tom Cave is said to have built a long focus 12" newtonian with 6% secondary. Is there a manufacturer with similar specs? A 12" newtonian with 6%...

I have a question about the use of a Meade LX-90. Specifically, if one gets the wedge, can one operate it just like an "old school" clock drive fork-mount...

Product Review by David Knisely 30mm WIDE SCAN Type III Eyepiece Available from Astrosystems $225 The popularity of wide-field eyepieces has surged in...

Hello, I want to re-start my astronomy hobby. About 15 years ago, I owned a 80mm refractor, which I used to look at planets. Then went to university etc,...

I believe there are 100 billion stars in our galaxy and 100 billion galaxies in our Universe so even if the probability of life is very small there are high...

as for the rain, cold, clouds, cold, fog, cold, smoke, cold, bad seeing conditions, cold, lights, Did I mention cold? Any ideas? Hi: The advantages of...

Anyone got a 8" Deep Space Hunter from Modern Throught? Is it any good? Is the mirror any good. I know it's Plate glass but that ain't all that bad in a 8...

Hey Bill, This is very nearly exactly what I saw with my Meade 12.5 inch on Tuesday morning at around 0800 UT. The extra aperture and slightly more...

Hi: I'm planning to buy a telescope for my son. My budget including all accessories is $500. I've done some research on various websites including...

If anyone would like a pair of Oberwerk 15x70's, I am selling a pair for $99 + $5 shipping. They are in brand new condition. I've had them for three months,...