Commercial Dobs

I am curious as to your impressions of the commercial Dobsonian scopes. In particular:

1. Starmaster
2. Obsession
3. Discovery
4. Port-a-ball
5. Starsplitter

Any opinions on how these scopes compare one to another would be appreciated!

Thanks,

John R.

Well, I don't have much experience with the others, but I am currently on my third Starmaster. I think that says something in itself! My first Starmaster was a 14.5" w/goto, and I currently have an 18" f/4.2 w/goto and Pegasus mirror, as well as an 11" f/5.4 ELT/Zambuto. Not only are Rick's scopes outstanding, but the customer service is amazing. Rick is fond of saying that his customer service goes with the telescope, not just the customer. As an example, when he delivered my used 18" to me, he noticed that the drive wheel was worn, as was the glassboard on the rocker box. He replaced both before delivery. I am not sure that you would get that from anyone else.

I prefer the wiffle tree support for the mirror to a sling. Just a personal preference I realize, but it holds collimation better through the night, and that is a fact. I also like the fact that Rick tests each and every telescope before he ships it, so you are assured of receiving a telescope with a mirror that has actually been observed through, rather than just drop shipped from the mirror coater. The thinner 1.6" mirrors that are used in the sizes under 24" cool much faster than a full thickness mirror too. Contrary to what one scope maker claims, these mirrors do NOT exhibit astigmatism because the wiffle tree cell supports them in exactly the same way the testing bench used by the mirror maker does.

I also like the truss arrangement in the Starmaster better. They are set up in a triangle configuration so that you install two sets of trusses at a time. Makes setup faster, and you can set the upper cage on top of the trusses while you bolt it down. This is much easier than trying to set 8 separate poles into clamps in the upper cage. In addition, there is a goto/tracking system you can get on the 14.5" sizes and larger, but it is kind of expensive.

Keep in mind that this is MY opinion, and I don't need any flames from the owners of any of the other makes! But, I did my research thoroughly before I ordered my first Starmaster, and have been satisfied enough to buy two more.

Oh yeah, another excellent brand to throw into the mix is Nightsky. Uses a similar mirror cell and truss configuration as the Starmaster, and Jim Nadeau is a super guy to work with as well. I may be biased, however, as I consider Jim a friend!

Doug
Midway, FL

You might do well to include Nightsky scopes on your list.

http://www.nightskyscopes.com/

I own a Nightsky 16 and feel it compares favorably with the scopes on your list that I'm familiar with.

Lowell

I have tried a few of these.Namely the Starmaster, Obsession,and the Portaball.I found the optics to be nice on all.The only drawback to the portaball in my opinion is the "daintyness"(is that a word?)A little more balance problems with heavier ep's than the wooden dobs.I also noticed you can lean on the wooden dobs a bit more without seriously knocking them around,but the portaball will move almost too easily.The portaball does however reduce into a very nice little neat package.Much more so than any of the others.If you're limited to space or drive a compact,it might still be for you.I really like my Starmaster 10 inch.Very sturdy.I'm like a bull in a China shop so it suits me well.It is the older EL model that has the one piece truss assembly.I love this feature since it doesn't need collimating every time and can be set up in close to a minute.The only drawback is the space it takes to transport it in only three pieces.Since the only Obsession i've used is a friend's 20 inch,what can i say except quote the owner"Aperture rules dude!" The mechanics are smooth and flawless.Takes a lot of effort to transport and setup,then collimate.So,unless you have dark skies or can leave it setup in your backyard,it would be a consideration of mine as to whether i would get to use it much.He uses his probably 1-2 times a month on average(if he's lucky)You can also check out Ed Ting's review site.I'm sure he's reviewed most of them if not all.Another quote from a club member:"The best scope is the one you use the most" Don