Posts Made By: Chris Gorman

Ok, I'm fairly new to the hobby and need some help. I'm thinking about piecing together my own scope. I have a 10" F/5 tube and need a primary mirror to go with it. I found a 10" F/4.5 and 10" F/4.8 primary mirror. What do I have to do to get these mirrors to work with my F/5 tube? Can I just lower the spider/secondary down a bit in the tube? Or do I have to bring the primary mirror cell up? Any opinion on which focal ratio mirror to go with?

BTW, what size secondary should I use for this scope? Thanks in advance!

As astronomers, we have our usual suspects to observe at nights. Saturn, Jupiter, the moon, M31, M13, M42, etc. However, if you think about it, there aren't a lot of objects in our sky that really are worth looking at unless you have a huge telescope. Which begs the question, how good are our galactic genes?

I mean, wouldn't it be great if we had:

3 or 4 moons around the Earth

20 planets in our solar system(with about 5 or 6 that are like Jupiter/Saturn and can easily be seen in a small scope and show great detail)

20+ M31 type galaxies up in the night sky

10 or so M42's

etc etc.

All of these objects would be different shapes and colors. As astronomers this would be total bliss. Can you just imagine having 10 or so M42's up in the night sky? All 10 would fill up a medium powered ep and still be totally unique in shape and color.

Please, for the moment suspend your disbelief. In other words no comments like "Well, if we had 3-4 moons this would cause too much light blah blah blah.....

Just look up in the night sky and think to yourself "What if?".

Of course the irony behind this is the simple expression "Thank your lucky stars for what you have now". How true, how true.

I'm looking to buy an ep in the 10mm range. Has anybody tried these new XW series ep's? I liked the older Pentax XL 10.5mm ep, actually I prefered it over the 9mm Nagler type 6. So I'm assuming these new Pentax designs will be even better. Any comments on them?

I'm looking for a new spider and secondary for a 10" dob. Has anybody here gone with a 3 vane spider? According to ProtoStar's website, a 3 vane spider will produce higher contrast because the defraction spikes aren't as great. Is this really true?

ProtoStar sells a pyrex secondary mirror, but they also now sell a Quartz secondary. Are these Quartz secondary mirrors worth the extra cost? Or will I probably not see a difference? Thanks in advance.

What was your most disappointing telescope purchase? Anybody spend a lot of money on a scope and it turns out it wasn't what you were expecting? I'm just curious to see what scopes are mentioned. As for me, I have only owned one scope(10" dob), so I don't have any stories yet.

Is there really a big difference between say a Zambuto 10" mirror vs. a Meade or Orion 10" mirror? Basically what I'm trying to ask is does every mirror in a 10" Meade or Orion dob have some type of imperfection with it? Are some of them Zambuto quality? How close are they to Zambuto?

I know Zambuto probably uses better coatings. But I'm not really asking about coatings, I'm really mostly just asking about the mirror shape.

After being out of the hobby for almost two years, I'm now starting to get back into it. I'm piecing together my own 10" dob and was planning on getting some high quality ep's. I love the 17mm Nagler Type 4 and the high powered Pentax ep's. So those are on my buy list. I also would like to get a very nice low power ep, like the 31mm Nagler or one of the new Pentax 30mm or 40mm ep's(70 degree FOV). However, after reading some comments about binoviewers, I have become confused on what to do.

Which route should I take? I have never looked through a binoviewer. Current binoviewer owners, do you only use your binoviewer now or do you still use your single ep's?? If I go with the binoviewer I would get the Denkmeier Two(which runs about $1,100).

I'm curious about which low and medium power ep's are most recommended for binoviewers. Can you give me a couple of your favorite combinations? Is it possible to use the 17mm Nagler Type 4, or is it too big? Can you use 2" ep's in a binoviewer?

I just posted a message about binoviewers, which got me thinking about binocular telescopes. After thinking about it for a while I'm wondering to myself why aren't binocular telescopes(reflectors) more popular? And don't say cost and size. Light buckets in the 8"-15" range don't cost a lot compared to 4"-6" APO's. And size could be fixed by using a truss design.

Has anybody ever looked through a binocular telescope? Does a bino-scope make it seem that you are viewing through much larger optics? In other words does a 15" bino-scope feel like a 20" mono-scope?

Ok, you get one telescope of your choice for a whole year. What would that telescope be? A couple of rules:

1. The telescope can only be setup by one person, no help from others. So I don't want to see anybody list a 10" refractor or 40" dob(etc.). It has to be within reason.

2. You can also pick a mount for the scope(GOTO and DSC if you like).

3. No other options can be listed. So in other words no 25" dob with a 6" AP finderscope.

4. If you already own the scope you list that is fine. Consider yourself lucky.

5. It has to be a telescope, so no big Fujinon binoculars(etc.) can be picked.

6. I forgot to mention this rule. This is the only telescope you can use for the entire year. You will not have access to any other scopes.

I will start. My choice is an 18" Obsession with the ServoCat GOTO and Argo Navis DSC. It's still a portable scope, fairly easy to setup, it doesn't require a ladder, it's much smaller than the 20" Obsession, it has full GOTO capabilities, and it gathers a ton of light.

Really this is about your ideal/dream scope, or which scope you hope to obtain sometime in the future.

I have some questions about light pollution. If you live in a medium size city, how far away would you have to go to escape its light pollution? Are we talking 50-75 miles here?

Where are some extremely dark observing locations in the US? I'm more interested in the locations that are in the eastern half of the US.