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12-inch premium Dob

Started by Inge_S, 08/01/2002 11:45AM
Posted 08/01/2002 11:45AM Opening Post
I have used an 8-inch Portaball for two years, and I'm highly satisfied with it. However, there's always a desire to go deeper in limiting magnitude and increase resolving power, and I'm seriously considering to upgrade to the 12.5-inch PB. Before making my final decision, however, I thought it would make sense to look at other alternatives. There are very few Portaballs available on the second-hand market, but occasionally I see other fine Dobs in the 11 - 14-inch range for sale. The 11-inch Starmasters look very nice to me, and I'm open to other alternatives with fine optics.

What bothers me a bit, however, is portability, set-up time, and general ease of operation. I'm also concerned about ergonomics, after two years with the Portaball, I'm spoiled. How does e.g. the 11-inch Starmaster EL compare with the 12.5-inch Portaball in these respects? Are there other alternatives around? Any comments are welcome.
Posted 08/01/2002 12:03PM #1
I don't think you will find anything as portable and easy to set-up / breakdown as the 12.5 Ball. However, the Starmasters are an excellent option and do allow the use of setting circles, a feature your not likely to be using that much since you have the 8" Ball now.

Much can be said of Pete's 12.5" scope. I think it is the best in his line and offers the best combination of portability, optics and light gathering power. You are correct that not many people sell these and that says something. By-the-way, many of the balance problems in the 8" are not existent in the 12.5".

Posted 08/01/2002 03:31PM #2

I also own an 8" Portaball, and I've been wishing for more aperature. Before I started looking through other telescopes, I thought that I might want something like a 15" Obsession. Once I'd looked through other 'scopes, I decided that a Zambuto mirror is a must in a larger telescope.

This leads to a 12.5" Portaball or a comparable (or perhaps larger!) telescope from Starmaster. After considering all of the factors that are important to me, I've come to the conclusion that a 12.5" Portaball is the correct answer for me. (With the 8", I leave all of the equipment that is not very temperature sensitive in the trunk of the car in a duffle bag. When it's time to go observing, I seatbelt the Portaball in a passenger seat, and put the base and eyepiece case in the trunk. I'm ready to go in a couple of minutes. I want to be able to have that sort of convenience in a larger 'scope as well.)_

I do plan to get the transport cart so that I can move the telescope more easily once I arrive at my dark sky site. (I'm also considering an equatorial platform so that I can do extended observations of objects with more comfort.)

Once I've saved the necessary $2000, I'll place my order.

Best Astronomical Wishes,

Barry R. Fernelius
Posted 08/01/2002 11:58PM #3
After a lot of thought, I went with the 12.5" Portaball with eq platform as well, after playing with various dobs and then a Portaball at a star party. Modern dobs are pretty slick and maneuverable... but the Portaball was a blast to work with ( as you know! ). I considered the 14.5, but opted for the 12.5".

Staying with zambuto mirrors...
The starmasters also look very nice..
and you might also look at the teleport. I demoed one last month and it's pretty darn nifty.

I'm sure that the Obsession would be nice as well.. but with a 15" wouldn't you be stepping up to a stepladder? ( Literally ... or have a very fast dob? )... and Inge seems to be concerned about portability and weight?

I may be asking to be flamed, but I've always been impressed with how well 12.5" zambutos/swayzes seem to image vs cheaper 15" and 16" mirrors. ( Collimation helps loads, though ). The half mag depth gained didn't seem to outweigh other performance factors, in my eye. ( again, literally ).

A signficant consideration may be delivery time! Last I looked, I think the starmasters and teleports are booked up through 2003?

Also, one of the reasons why I went with the Portaball is that there ARE so FEW of them for sale. That seemed to speak loads as to how much their owners value 'em.
Posted 08/02/2002 06:34AM #4
I used Rick Singmaster's 11" Starmaster Shorty for a couple of hours last year at the Black Forest Star Party and was extremely impressed with it.

However, as good as Starmasters are I don't think that they, and Obsessions for that matter, can begin to compare to the way Portaballs handle. I had a blast manuvering a 10" Portaball through the summer sky at Cherry Springs State Park a few weeks ago.

Dave Mitsky

Chance favors the prepared mind.

De gustibus non est disputandum.