Posts Made By: Chris Gorman

I'm thinking about buying an 18" dob. On paper, the jump from a 10" dob to an 18" dob is pretty large. But I was wondering how big of a jump it is when looking through the eyepiece. Is there a substantial difference? A night and day difference?

I found a real nice dark site near me, and my 10" performs well. I'm just curious how much better an 18" would be.

I'm looking to upgrade to a large dob(probably 18"). I wanted to get your opinions on which brand you like better and why. Yes, I know you can't go wrong with either one, but the fact is each one has its advantages and disadvantages. I have never seen one of these scopes in person, only pictures.

Obsessions seem to have the high quality furniture look to them. Starmasters are no slouch, but they don't look quite as good as Obsession scopes. But I'm just going on the pictures I have seen of these scopes.

In terms of mirror, well I'm not sure that a Zambuto is really any better than a Torus(the mirror I would go with if I bought an Obsession). The thing that I like about Torus is they test each mirror and post the results on their website(with pictures of the test results). Still, Zambuto mirrors do have that cache about them.

I like the fact that Starmaster rigorously test each telescope(including the mirror) that it sells. I don't believe that Obsession does this. To me the testing that Starmaster does is a nice selling point.

Ok, bottom line, which brand would you choose? I would like to hear from people who have seen(and preferable used) these scopes in person. I know there are other brands of dobs to choose from out there, but I have narrowed it down to these two. And please, I don't want any of these types of responses: "Well, you can't go wrong with either one". You have to pick one or the other. Thanks!

Aoccdrnig to rscheearch at an Elingsh uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, olny taht the frist and lsat ltteres are at the rghit pcleas. The rset can be a toatl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae we do not raed ervey lteter by ilstef, but the wrod as a wlohe.

I'm putting together a dob. My tubes outer diameter is 12.5", inner diameter is 11.75". My mirror is a 10" f/5.52 and it's 1.6" thick. I'm thinking the hole should be about 5.65" from the front of the tube, but I don't know if that is correct. Also, whatever figure you give me, is that from the front of the tube to the center of the focuser hole? I'm assuming it is. Thanks for your help!

Well, I decided I'm going to buy a small refractor. Should I go for the TV-76 or the Orion 80mm ED? The TV-76 complete package is about $1675(which includes an everbrite diagonal, soft case and a 20mm TV plossl ep). The Orion sells for $500 but by the time you add a diagonal and a soft case the price rises to about $800.

The scope will be used for wide field astronomical observing and I also plan to use it for day time observing(birding). From the reviews I have read it seems the Orion is a pretty good astronomical scope. So I guess the question I should ask how good is it for birding, etc. I'm wondering if the daytime performance will show its "flaws" more.

I was thinking something like the Bogen 3021, it has a maximum load of 13.3 pounds. Can I get away with a 13.3 pound rated tripod with the TV-76? The maximum weight of the TV-76 will be about 10.5 pounds(I will be using a binoviewer with it). Or would I be better off going with say the 3046(26.5 pound maximum load)?

What about head suggestions? Are the Tele-pod heads any good? Which Bogen heads would work well with a TV-76? Thanks.

I would like to see Tele Vue start making a high powered Panoptic line. They have the Radians, which have great eye relief but not a large FOV. They have the Naglers with a huge FOV but not a lot of eye relief. What about a high powered Panoptic line, which would have more eye relief than the Naglers and a larger FOV than the Radians?


Is this possible?

Guys, help me decide. The 10" Discovery DHQ is about $650. The 9" TMB is about $29,000. The bad thing about the 10" Discovery is it's going to cost another $70 for shipping. I think I might be able to swing free shipping on the TMB. The TMB only comes with the optical tube. The Discovery comes with two plossl ep's and a free color filter set.

Has anybody compared these two scopes side by side? I just can't seem to make a decision. Any advice? I'm leaning towards the Discovery, that free color filter set is very enticing.

BTW, the mount for the TMB is going to cost me another $15,000-$30,000. So please take that into consideration.

uncomfortable scope to use. Tonight I did some observing with my 10" F/5.5 dob and must say that my body has never been in so many awkward positions. I made Yoga look like child's play, although I've never tried yoga.

The problem with a 10" dob(around F/5) is it's too short to use it standing up, but too tall to use it sitting down. There is never a comfortable position.

Damn you 10" dob! Ok, I didn't mean that. Now where did I put the Advil?

I offset the secondary in my 10" dob. I used a laser collimator to line up the secondary with the primary, then I used the barlowed laser technique to align the primary. However, when I did a star test the secondary reflection was not in the exact center of the defocused star. Is it supposed to be? Since the secondary is offset I thought that might be the reason why.