Tuesday, December 13, 2011

Logic of Acquisition

I own four telescopes, two of which I seldom use. I think this might be typical in this hobby for anyone who has gone beyond the beginner stage. Some of  this can probably be attributed to the need to have the latest neat thing. But the root cause stems I think from the fact that no one telescope is good at everything. An amateur's interests can change over a span of years and the need to have a telescope to fit new tastes leads to the slow building of a small fleet of telescopes. I'll cite my case as an example of the purchasing logic that can apply.

In 1998 my wife and I went to see a total solar eclipse in Aruba. At the time I had no working telescopes, so I picked up a "grab and go" Short-Tube 80 from Orion. The ST-80 worked well on a simple tripod, for which I purchased a three-axis head. This worked great in Aruba, both then and in 1986 when we returned.

The ST-80 is a great little telescope, but not very good at showing the planets or double stars. By the next year I was finding myself getting interested in the Astronomical League's observing lists, starting with the Telescopic Messier and Double Star lists. I needed a little more aperture and a longer focal length. Another refractor would do, but the flood of good, economical overseas glass was yet to happen.  INTES Maksutovs were getting great reviews, though, so I picked up an MK-67: A fixed-mirror Maksutov-Cassegrain with 150 mm of aperture and 1800 mm focal length. I used it to do those two lists.  The MK-67 was so good I was able to see Pluto (while it still was a planet, so now I've seen all 9).

The next list I went after was the Herschel 400. This list is more demanding than the Messier list, and needs larger aperture than 150 mm.  Always budget-minded, I opted for a 250 mm Newtonian/Dobsonian telescope from Orion. I finished the H400 list with that, and did most of the Caldwell list too.

I had the misfortune in 2001 to look through a Tele-vue 102 at a dark-sky star party.  I was greatly impressed with the views it provided. Several years later the same telescope was put up for sale and in 2004 it became mine. My conversion from a "reflector guy" ended. I considered the TV-102 as a versatile lifetime scope, which in part justified the cost.

In 2007 and 2008 I became interested in astrophotography.  I started with Solar System webcam imaging that put the MK-67 to good use.  Then I noticed what people were doing with DSLRs, so I got a consumer Canon DSLR and put it to work, first with the ST-80 and then the TV-102. No additional telescopes were needed, but I did get a new mount in 2010 that was better able to carry the combined weight of the two telescopes. (usually the TV-102 is used for imaging and the ST-80 for guiding.)

In early 2011 I purchased a used CCD camera and have been learning CCD imaging since then.  The DSLR is being used mainly as a vacation camera. The MK-67 I hope to put to use for small-field objects, despite its slowness at f/12. The Dob sits around gathering dust, as it's basically worthless for anything other than visual observing. I plan to replace the mirror eventually, remount the scope with rings and use it for imaging, but that remains to be seen.

Each new telescope fulfilled a developing need in my hobby.  Next up is to move to wide-field narrowband imaging either by buying an adapter so that I can use the DSLR's lenses, or--if I win  the lottery--purchase a small refractor like the Astro-Tech AT65EDQ.

Next time: We Interrupt Our Regular Programming



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