About to Buy a Large (20

All of you have been very helpful to me with my numerous questions this past year. I appreciate it. I sold my Meade 12" LX200 and am about to buy a large dob in the next day or so: either an Obsession 20" or a NightSky 22" with Argo Navis/Servo Cat.

I just had a final question or issue--last minute jitters, if you will.

I am an experienced observer, though more intermediate than advanced, almost all viewing done with with large scts (8"-16"), but I am not what I (mistakenly?) think of as a typical hobbyist. I do not have a formal physics, mathematical, or engineering background. I just like observing and am self taught.

The move to a large Dob is for visual impact and enjoyment. I want to be wowed and liked the views at the 16" level. I have no plans for photography nor any real desire to do it.

It has not been possible to "do the right thing" and go to various star parties and engage in due diligence, though I have tried. Not many large dobs in central Maine. I did go to Stellafane 2004 and looked at the various dobs between rainshowers.

I have a young family and am a trial attorney with a wacky schedule. I view 1 or 2 times a month.

The Meade 12" LX 200 was a bear to set up. I am 34 and in excellent shape, but the Meade was a bit of a pain, although it was a very nice scope.

I like the NightSky Dob for various reasons (especially Jim Nadeau's helpful responses; Dave Kriege has been really good, as well), especially with the electronics package, which helps to keep the clutter down.

I am prepared for a large dob, a ladder, and the bulk.

I just want to make sure that I am not going crazy. This is an extreme luxury that I will use regularly, but somewhat occasionally. I know that going into this.

Anyone out there who made the jump from a medium/large sct (or small/medium dob) to a very large dob (and maybe with little actual experience before buying the large dob) who is unhappy or felt they made a mistake?

Lastly, any thoughts on 20" v. 22" and enhanced coatings (Obsession) v. standard coatings (NightSky). I do like planetary viewing, but equally enjoy deep sky.

Any other advice, as well, is appreciated.

Gregg D. Bernstein
Augusta, Maine

Gregg,

Welcome to the aperture fever ward.

I graduated from a 10" SCT to an 18" dob. You do need to consider that going to a large aperture mirror will increase and complicate the logistics of observing. Unlike you, I've kept my 10". Although it's a bear to lug around, it's still easier to set up and use than the 18". I'm 5'7" and in good shape for 61. Your setup and adjustment tasks will be considerably more extensive, as well.

On the other hand, viewing through a larger aperture scope will be superb, especially when you're able to get to dark skies. You'll be enoying a much wider breadth and depth of objects. I've never looked back.

Clear Skies,
Howard

A good friend just got an 18" f/4.5 Obsession and just loves it. Large aperture, easy to move about and since he's a 6 footer, he doesn't need a ladder to get to the eyepiece.

Don Wyman

...Zambuto-equipped Starmasters (used) can be had for way below new prices. Just something to think about...once their "depreciation" is subtracted, they hold their value really well.

Doug

Gregg
I am a badly obsessed visual astronomer and may have as bad a case of aperture fever as anybody I know. I own a 40 inch f5 Dob in a roll off roof at a dark site. I have several premium refractors and equatorial mounts to put them on. The scope I use the most is a 20 inch Starmaster that sits fully assembled in my garage (the car stays outside,it is worth much less to me than my 20 Starmaster.) I envelop the whole scope in a tarp which keeps the mirror clean. I can roll the scope out on the driveway, initialize on two stars, engage the GoTo system, and be observing before the 4 minute timer turns off the garage light. It is ironic that the largest scope I have at my house is the quickest set up, and the one I use the most. When the medium and deep blue seeing on the clear sky clock are present, the best planetary and lunar images I get are from this 20 inch Starmaster, better than can be had in Zeiss and AP refractors that are sitting side by side with this 20 inch. The Zambuto optics in the Starmaster scopes are absolutely superb. Deep sky images are amazing. I have seen Pease 1, the planetary in M15 from my driveway in mag 5.2 skies with this scope. Look through the CCD forum at the planetary and lunar images that Wes posts that are taken in Oklahoma using a 14 inch Starmaster and now an 18 inch Starmaster. I have personally visually seen a view of Mars during the last opposition that looked like the Mars image he has posted on the Starmaster web site.
I don't think for a minute that you should hesitate to go for the 20 inch aperture. I would encourage you to acquire a scope that is as easy to use as my 20 inch Starmaster is. I cannot compare the ease of use and images in an Obsession to the ones I see in my Starmaster. I can tell you that you would never be disappointed with an 18 or 20 inch Starmaster.

Hello Gregg,
First of all, do you have the vehicle that is capable of transporting this large scope.
Do you have the physical ability to single handed set up a large scope. Make sure you know what the minimum weight is for the lightest component and the maximum weight for the heaviest component. These are not usually a 5-7 minute set up like my 14.5" Starmaster or the 15" or 12.5" Collett Dobs I own. So you must have time to set up and tear down in your schedule. Plus the big mirror will take a little longer to cool down. Most will require you to use a step ladder too.
This said, the view through these large scopes is superb. Great resolution and brilliant DSO's.
Now, if you are going to splurge on a big fine Dob, you should consider the quality of the optics and the scope structure. Some scopes might look good at a stand off distance and yet fail the visual when you look up close
They might use construction grade wood instead of cabinet grade or the mirror cell might be not a precision. I have looked at a few and I was disappointed with half of them.
I would suggest that you need to see them in person and take a very close look at everything, including the craftsmanship and cabinet making skills as well as materials used in construction. Take a measuring tape with you and check to see how square things are and whether the measurement are equal in the primary cell and other parts. This will give you a general impression of the quality of the build. This quality will insure that the scope will hold it's value and stay together and collimated.
Everyone thinks that their scope is the best, so you can not just take the brochures work for it and pictures tend to show the best of the highlights not the worst.
Starmaster is a quality scope with fine finish and good construction. It is not without faults, but the overall is very good. The finish and details are excellent compared to other scopes I have seen. There are areas that I feel should have had more strength such as the alt bearing mounting with wood screws, the az and alt bearing material just being nailed on instead of screwed or in the az, glued to the base board and the rocker box being assembled with screws instead of finger joints and glue. Zambuto optics are world renowned as a bonus though. The Go-To is very nice with excellent installation and wiring.
Obsession is well built and seems to be made of quality materials. Finish is pretty good and material seem good. Optically they have some good mirrors available.
Night Sky is a nice scope and thee Go-To is very precise but the installation of th G0-To is a bit unorganized with a lot of wires that are poorly routed. The quality of the wood is fair with a bit of construction quality plywood used. The finish is fair with some of the interior areas lacking and some roughness is found in a lot of the areas. The router work is not that smooth and there was little attention paid to the sanding and finish where the routing was done. Optics available are good.
Now I am not wanting anyone to get upset if I just said something that they did not appreciate, I am just making statements based on what I have seen.
In conclusion, do not just look at the price tag, look at the performance, quality construction and optical quality when making your purchase. It also matters that you like the look and feel of the scope, this is your toy and you need to enjoy playing with it.
Ok, that is all I have to say on the subject. : Flame me if you must, for I have stepped on some toes here.
Floyd

Hi Michael,
First off, when I left comments on the Starmaster group, I had not had the scope long and had not really gotten a chance to look at it critically. I also know that it is not a good idea to say too many bad things about a product on it's own owners group forum. You tend to be labeled as a trouble maker and a Non Group kind of person.
I told everyone here that I would give an honest opinion on the Starmaster as I got enough information and eyepiece time to acquire the necessary data to make comments mean something.
I am not trying to say that the Starmaster is not a fine scope, but rather I am pointing out that the scope is not perfect and does have things that were not done in the best way possible. I find this to be true with the Night Sky and the Obsession too. In fact I have not seen any scope so far that did not catch my critical eye.
I want you to know that I do like the look of your scopes. The build seems quite good and attention to detail appears excellent. I did consider one of your scopes when I made this last purchase, but quite frankly the price of your scope was a lot more than I paid for the Starmaster. I did not have the price of admission to buy your scope, so I looked for the best buy I could find in a used scope of the required size and focal length. If there had been one of your scopes out there offered to me I might have taken it.
I do agree that there have been a few scopes that are very good that were not mentioned in this thread so far. Yours for one, T-Scopes, Starsplitter for a couple of others. This is still not a complete list for sure and when you are looking to buy a new scope these and many others should be considered.
I think that the Zambuto mirror was a big factor in my decision. The rest of the scope was fine to, but I must admit that I do like some of the ideas and hardware that my other two scopes have. I still have not had a chance to determine just how much better the Zambuto is than the Swayze in my other scope. I hope for some good weather soon to try and determine this.
I am also going to compare side by side the Night Sky 14.5" with a John Hall mirror to my Starmaster at a friends house and observation site. We are going to use the same EP to evaluate the views of many objects in an evening to see which mirror and scope shows the most detail, contrast and brilliance. I will give an honest and unbiased opinion on this when we get the chance to do the test.
I would like everyone here to tell it like it is with their equipment, so that all that read the information are hearing their true feelings about it.
Floyd

Thank you all for your very up front and informative opinions. I am fortunate to have so many people who do not know me provide excellent advice and constructive criticism regarding the various scopes I have been considering.

I have been waiting so long to make a decision and it seems to be getting harder as crunch time nears.

Thank you again.

Have a great new year.

Gregg D. Bernstein
Augusta, Maine

Michael, you sure are making sweet-looking scopes these days!

Micheal,

I agree. There is plenty of room for improvements or advances for the truss dob. One thing I've realized is that one person's necessity is another person's extravagance.

What improvements would you like to see?

I would like to see the weight go down, better electical packages, less costly GOTO. Maybe we're begining to see the turn away from wood as the structure material.

I also agree with Doug that your scopes are quite nice looking.

Mark