Wellll, it's been both head cold and weather cold time for me. Clear and cold nights have coincided with my lingering head cold, so I have no news to report.
The Tale? Earlier today I spotted a for-sale ad on Cloudy nights from the person who sold me my used AT72ED. He sold that scope because he wanted to move to something larger, an AT111EDT. He bought the AT111 and sold his AT72 thinking he no longer needed it, and that the smaller scope would help pay for the bigger scope. Sensible plan, really; how many scopes can a person use at one time?
The AT111 weighs 11.2 pounds compared to the AT72's 5 pounds, and perhaps more important is larger and a little more difficult to handle. I know my TV-102 surprised me at how large it was and how careful I had to be when moving it around. Not the the 102 is fragile, but I think that refractors in general are deceptively small in appearance.Once you start carting them around you find out otherwise. Just ask anyone who owns a 6-inch refractor--it doesn't have the same portability as a 6-inch Dob!
Sadly, the AT72 seller developed back problems that needed surgery to correct, and his new AT111 is now too much for him to handle. He's put it up for sale. It's unknown if the larger scope caused his back problems. I sort of doubt it, as back problems can reassert themselves for no clear reason at all.
The caution to this tale? It's tempting to suggest that one should never sell one's telescope, but that's utterly illogical and makes little economic sense. And besides, if everyone did that, where would I get my telescopes?
I think the lesson here, if there is one, is that a factor in deciding when to sell a telescope should be the "niche" it fills in your hobby. The AT111 and AT72 are different enough that they can serve different purposes; the former is a serious scope good for almost any purpose, while the latter is a great grab-and-go scope.
Sorry for this. I know it's not as if you wanted another reason to anticipate "seller's remorse." But it can and does happen.
Showing posts with label Buying telscopes. Show all posts
Showing posts with label Buying telscopes. Show all posts
Saturday, February 11, 2012
Monday, January 2, 2012
Buying a first telescope
I have started or resumed this hobby four times, so in a way I have had four "starter" telescopes.
The first one was when I was a child, about ten years old. It was a Gilbert 2.5" Newtonian--which explains the sig line I use in my astro club's forum. Shoddy mount, shoddy tripod, shoddy finder, shoddy eyepiece, shoddy focuser, etc. In all ways it was inferior, but I loved it; I was a patient little kid, and was willing to fight that telescope for every view I could wrestle from it. For the astronomy-interested child with the right temperment, any telescope is like a piece of heaven on earth. Even the much-maligned department store scopes will serve. But I would advise buying something better.
Teenager: 6" f/8 Edmund Newtonian on a GEM. Darned good scope.
Graduate Student: 8" f/6 Meade Newtonian on a GEM. Also a darned good scope.
Adult (at least chronologically): ST80 Refractor on a GEM. Then a 6" f/12 Mak-Cass followed by a 10" Dob, then a 4" apo, and last a 72mm ED.
Lesson: Don't sweat the decision on the first telescope too much, as you will soon decide it is not completely adequate for your needs. It's good to start with a general purpose scope. Using it you will learn about telescopes, and about yourself: What you like to see, What you're willing to put up with, What you want in terms of bells and whistles. Then when it's time you'll better know what you want in The Next Scope.
My 6 and 8" Newts were close to being perfect general purpose scopes. Both had 48" focal lengths, which made them useful for planetary observing without having to resort to really short focal length eyepieces. They were at what seems like a nice balance point between fast and slow, so faint fuzzies were OK in them. Which one to get depends on the subjective factor of portability. The 6" was much lighter than the 8".
All that said, I agree with the advice of a 6" or 8" Dob. If you're thinking you really like looking at solar system objects go with a GEM that has a drive for right ascension. If instead your heart beats faster thinking of the faint fuzzies, get yourself an erect-image finder. That really helps with star hopping.
Speaking of star hopping, I'm old school. I think that Go-To drives are are appropriate in many situations, but not on a first telescope.
Telescopes are tools you can use to extend your senses to a cosmic scale. When you learn how to use your telescope and get to know how it reacts--what it can do and how you can get the most out of it and yourself--you become a craftsperson versed in its use. That's when the connection between you and the cosmos becomes direct in a special way. This will sound a little metaphysical, but I think that's when the telescope becomes a part of you and no longer is an artificial interface between you and the sky. The joy of that sensation is one of the reasons I love astronomy.
The first one was when I was a child, about ten years old. It was a Gilbert 2.5" Newtonian--which explains the sig line I use in my astro club's forum. Shoddy mount, shoddy tripod, shoddy finder, shoddy eyepiece, shoddy focuser, etc. In all ways it was inferior, but I loved it; I was a patient little kid, and was willing to fight that telescope for every view I could wrestle from it. For the astronomy-interested child with the right temperment, any telescope is like a piece of heaven on earth. Even the much-maligned department store scopes will serve. But I would advise buying something better.
Teenager: 6" f/8 Edmund Newtonian on a GEM. Darned good scope.
Graduate Student: 8" f/6 Meade Newtonian on a GEM. Also a darned good scope.
Adult (at least chronologically): ST80 Refractor on a GEM. Then a 6" f/12 Mak-Cass followed by a 10" Dob, then a 4" apo, and last a 72mm ED.
Lesson: Don't sweat the decision on the first telescope too much, as you will soon decide it is not completely adequate for your needs. It's good to start with a general purpose scope. Using it you will learn about telescopes, and about yourself: What you like to see, What you're willing to put up with, What you want in terms of bells and whistles. Then when it's time you'll better know what you want in The Next Scope.
My 6 and 8" Newts were close to being perfect general purpose scopes. Both had 48" focal lengths, which made them useful for planetary observing without having to resort to really short focal length eyepieces. They were at what seems like a nice balance point between fast and slow, so faint fuzzies were OK in them. Which one to get depends on the subjective factor of portability. The 6" was much lighter than the 8".
All that said, I agree with the advice of a 6" or 8" Dob. If you're thinking you really like looking at solar system objects go with a GEM that has a drive for right ascension. If instead your heart beats faster thinking of the faint fuzzies, get yourself an erect-image finder. That really helps with star hopping.
Speaking of star hopping, I'm old school. I think that Go-To drives are are appropriate in many situations, but not on a first telescope.
Telescopes are tools you can use to extend your senses to a cosmic scale. When you learn how to use your telescope and get to know how it reacts--what it can do and how you can get the most out of it and yourself--you become a craftsperson versed in its use. That's when the connection between you and the cosmos becomes direct in a special way. This will sound a little metaphysical, but I think that's when the telescope becomes a part of you and no longer is an artificial interface between you and the sky. The joy of that sensation is one of the reasons I love astronomy.
Monday, December 19, 2011
Next Telescope?
I enjoy wide field imaging, and it's easier for someone like me who is learning astrophotography. Tracking errors are less evident, and the hardware to image is smaller and less heavy. The mount has an easier time carrying the load, and the smaller profile means wind presents less of a problem.
What should it be? I had my sights set on an AT65EDQ, a triplet with built-in field flattener:
When all is said and done, it's nearly $1,000.
Another option is to use the two Canon lenses I use with my XTi. This requires an SBIG adapter that costs $280:
What should it be? I had my sights set on an AT65EDQ, a triplet with built-in field flattener:
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| Astro-Tech AT65EDQ |
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| Typical Moonlight Focuser |
But it seems to be no longer for sale, and if it comes back it will probably have a long period on back order. The AT65's focuser is probably not capable of carrying my ST-8300M and filter wheel. So it almost demands a focuser upgrade, and that is expensive: Something like $400: Above is a high-quality Moonlight focuser that would be perfect.
Another option is to use the two Canon lenses I use with my XTi. This requires an SBIG adapter that costs $280:
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| SBIG EOS adapter for ST-8300 w/filter wheel |
This covers the focal length range from 17 to 70 mm, which is shorter than I want. If one of these were to pop up for sale used, I'd probably go for it for full constellation imaging. Moog adapters used to be available for this purpose, but their business has been scaled back and because of the filter wheel, this would require custom work on their part.
I already have a field flattener for my ST-80, so any short-focus telescope is basically ready for imaging. What I want is something with a better than average 2" dual-speed focuser and focal length less than 430 mm. The model I've read about that seems to have the best focuser is the AT72ED; new this is $380 and used usually round $250-$300. Another scope is the Stellarvue SV70ED, which also gets very good reviews.
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| Astro-Tech AT72ED |
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| Stellarvue SV70ED |
I've put in a "wanted" post on my club's web site, and I'm watching Cloudy Nights and Astromart for used scopes and SBIG-Canon lens adapters. I wonder how long it will take for something to show up.
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
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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