"America loved gorging on cheap imports; foreigners loved the rapid growth from shoveling goods to the insatiable U.S. market." That's what the Daily Herald said in an edi-torial about the current recession. In a way, that kind of describes amateur astronomers' buying habits. We all want to see more of what's out there and with a wide selection of equipment available these days, there's enough to feed any astronomer's lust. And many telescopes are relatively inexpensive by virtue of being mass produced in the Far East where costs are low.
In the International Year of Astronomy, we're reminded of the earliest telescope users whose aims were directed to-ward better quality instruments, rather than simply larger ones. Seventeenth Century technology just didn't allow for much larger telescopes; instead, astronomers had to con-tend with the poor quality optical glass and speculum metal mirrors of the day.
Jump forward 400 years. Optical quality is still on our minds when making some purchases. Astronomy author Geoff Gaherty, who has tested a large number of tele-scopes, noted that the earlier mass-produced products originating in the Far East suffered from uneven quality control - some were surprisingly good while others were of indifferent quality. Today the optics and features have im-proved, with uniformly high quality being the rule. He feels that current mass-produced Dobsonians - branded as Orion, Sky-Watcher, Meade, etc. - give 90% of the performance at about 30% of the price of a premium product like an Obsession or Starmaster. (And he personally owns a Starmaster.) In general, this also applies to many refractors and SCTs currently coming from the Far East. How-ever, this does depend on the company whose brand name is on the product; there are still some junky telescopes coming from fly-by-night outfits in the Orient. Those are usually sold in discount stores, or on eBay and the Home Shopping Network. Gaherty went on to point out that with the generally high quality of today's name brand tele-scopes, you do far better getting a larger mass-produced scope rather than upgrading a present primary mirror. The only exception might be if you obviously have a sub-standard mirror in your present telescope.
I thought of upgrading the mirror in my trusty twenty-year-old 10-inch Newtonian, but instead decided to get a 12-inch Orion XT12i Dobsonian. I'm glad I did that - the images compare very favorably with those in premium Dobsonians through which I've looked (taking into consideration any size differences) and the extra two inches of aperture has proved itself time and again.
Those who own premium Newtonians enjoy outstanding performance, but many owners and reviewers also ac-knowledge that on most nights the average observer wouldn't notice much difference in the images compared to those in a mass-produced scope. Only on rare nights with perfect seeing could you push a premium scope beyond anything you can see with the average mass-produced telescope. And some who have upgraded the primary mir-ror in their present scope report that the improvement is not as great as they had anticipated.
A couple of years ago I wrote a Night Times article on how to improve mass-produced Dobsonians. There are many tweaks that will make them better, but swapping out the primary mirror wouldn't gain much. I've also wondered about quality issues with glass types, since Pyrex mirrors are becoming less common. But analyses I've found show little difference in surface accuracy between soda-lime glass and Pyrex. It depends more on the care taken in grinding, polishing and figuring the mirror, especially with today's machine-generated optical mirrors, which produce more consistent results.
What this all boils down to is that while premium telescopes offer the best overall performance right out of the box, the popularity of today's mass-produced scopes at-tests to their performance versus cost attributes. No doubt that contributes in some way to our balance of payments with China and Taiwan. I hope there will always be outfits like Astro-Physics, Obsession and Starmaster around. The domestic producers face very tough competition from really good and much lower cost products coming out of the Far East under a variety of brand names. To appreciate this, consider that the Orion XX12 truss tube Dob with computerized object locator costs $1299, while the basic 12.5-inch Obsession runs $3295. Moreover, mass-produced scopes as large as 16 inches are becoming available; if you want anything larger than that, you'd obviously have to go the premium route. As a consumer ever watchful of what I spend, I'm very satisfied with my Chinese-made Dobsonian. I'd prefer that it were made in the USA, but it's results that count. Can't say I feel any remorse about that bit of economic perfidy.Published in the August 2009 issue of the NightTimes