Saturday, July 31, 2010

Where can I get advice on buying a telescope for viewing astronomical objects?

My level of interest is: serious amateur.


My main use will be to view planets, galaxies, nebulae, comets, the moon, the sun, etc.


I want to do some astrophotography with it.


It must have a motor drive, preferably GPS, and either a built-in database of celestial objects or an interface with a computer, so that I can easily locate known objects without a lot of time and effort


I'm willing to spend up to about $4,000.





I know of Sky %26amp; Telescope magazine, and of Astronomy magazine. Are there other magazines and/or websites that would help educate and guide me to choosing the best telescope for my purposes? I know I can just use a search engine, but thought I'd tap into people's experience with these and other sites.





I'm also interested in direct advice from any serious amateur (or expert!) on features and specs to look for, and quality brand names.Where can I get advice on buying a telescope for viewing astronomical objects?
The best forum is www.astromart.com. Cloudynights.com is OK but suffers from a few defects. For one thing it is over-moderated, people with strong opinions are often censored. For another thing is overly weighted with newbies in people on a tight budget. A better forum is Astromart. At your budget level you owe it to yourself.





There is a one-time joining fee of $12. If you go for a long period without logging on, or change your email, you may have to rejoin again.





What you get: It's the New York Stock Exchange of used equipment. You can learn tons just by cruising the ads. There is also an archive of old ads so you can get good price data before you buy used. What you also get: several dozen discussions group. The one you want is ';Equipment.'; (You're beyond the group for newbies).





I'm not going to offer you any advice. I've got several telescope configurations which I use on a variety of German Equatorial and one alt-azimuth dob. I have sunk four or five times what you've budgeted into the hobby over the years. The used market is a real blessing, helps save on a lot of critical items. It also means that if you don't like anything you can get most of your money back out of it.





Now, the astromart discussion groups are the best on the Internet, and here's why. We have a zillion Yahoo! groups on astronomy, but they are bad sources for information because if you go on a refractor group everyone loves refractors (for example); and even the supposedly ecumenical ';telescopes'; group is weighted to towards Newtonians in dobson configurations (almost any group that accommodates beginners will be); that's why you got the load of nonsense about charts from another post (I can go anywhere with or without a computer; charts are fine, I have several Atlases and sky software, and digital setting circles, so I am familiar with all the basic systems. A nice computer is hard to beat).





Take these things with you to Astromart to chew over:





reliability: go-to systems are more complex than non-go to. You can have tracking on a German equatorial, and pointing with a computer; this is called DSC systems. Argo Navis is the leading dsc bar none.





The computer: the options are plug in your laptop (the Software Bisque or Sky Map Pro, and other options); have a hand paddle with controls (most go-to systems) or a side attached box where you push the telescope to the object and stop where the system tells you to stop.





Environmental requirements: Working in extreme cold (under 20F) places different requirements. Dew is another killer. SCTs are extremely vulnerable to dew; refractors are ';fairly vulnerable';, Newtonians are most impervious.





Tracking: every configuration these days can track. For Dobson designs there is stellarCAT, almost all German equatorials track, that is their purpose in life.





Field rotation: notwithstanding that all telescopes can track, not all tracking is the same. Equatorial mounts maintain the same relative position to the sky. If you have a star in the center and a star ';on the left'; in your field of view, an hour later it will still be that way. On an alt-azimuth tracking system (dobs and fork mounted SCTs, usually) there will be field rotation. The star on the left will ';move'; to another position: over 12 hours it will move 180 degrees. Still in the same field of view, the star in the center still remain centered, but if you were doing a long exposure image, the star that has changed its rotational position will be a streak. A long galaxy would rotate in the field of view of an alt-az mounted scope like a plane propeller in super slow motion. I don't want to explain the geometry here but the basic schtick is: equatorial mounts=no field rotation, alt-azimuth=field rotation.





Photography requirements. The possible configurations are too many to discuss here. Do you want to image planets and the moon or galaxies and nebulae? The type of telescope you buy depends on your choice. For planets buy a Celestron 9.25 SCT. You want the combination of aperture and long focal length. For big nebulae get a small short focal length apochromatic refractor. For beginners in general short focal length instruments are more tolerant of tracking issues that bedevil newcomers. You'll have to decide between a ccd system and a digital single lens reflex (both used for deep sky) or a web cam (for planets) or get both. Stuff to talk about.





Stability: Not all configurations have the same stability in wind.





Other: Short exposure photography is more tolerant of different equipment configurations (short exposures reduce the importance of field rotation and jitters in the mount). As you prolong your exposure time you get more demanding of the mount.





Mount: In general the mount is extremely critical for any kind of imaging and you should plan on spending more on the mount than the optic. In terms of stability, weight combined with length, short fat and ugly is best. SCTs (short length, lots of aperture) and fast refractors (short focal length refractors) are the instruments of choice (as a rule). Newts are extremely cost effective but keeping them stable on a tracking mount is difficult.





One of the problems in your query is that you want one telescope to do it all, and that places contradictory requirements on the discussion. The best thing for visual observing, as one person here put it, is 8 to 10 inches (or more). The best thing for a beginner in photography is something that tolerates errors in tracking but introduces very little false color. The 80 to 102mm refractors that fit that bill are expensive, however, and offer more limited satisfaction on deep sky (but actually there's a lot to be done with a 102mm refractor and just an eyepiece). It might be that a Celestron 8'; or a Celestron 9.25 on the comes-with German equatorial mount will be what you want for visual; if you buy a 60mm refractor on the side, you might be able to get your feet wet with nebula imaging. I agree with another post that ';imaging without frustration'; is more of a $10 to $20k proposition but it can be done on $4k. Hell I've taken pictures of the moon through my $200 family camera: for $15 I bought an adapter that screws it on to my eyepiece. Not good on other stuff, though.





Other things to think about: Meade no longer has a rep for quality. It is near bankruptcy. Check the archives on Yahoo! sct-user group. Planet imaging requires huge hard drives because you're in effect taking home movies and then processing them using statistical software like registax. Vixen is probably the best intermediate brand name, best in terms of quality reliability (mounts and optics). Losmandy is good too (mounts); Celestron is much better than Meade at this point. I generally stay away from anything from mainland China if there is any possibility of doing so. (Vixen is Japanese and outsources some low end stuff to China, but they are very serious about quality control; you take your chances. The high end names are all beyond your budget but include Takahashi (optics), TEC (optics), Astro-Physics (for mounts; their telescopes can only be bought used); Planewave (optics); RCOS (optics) and so on.





AFTER you have made some critical equipment choices, the various Yahoo groups are excellent places to get support and information. People will share how they have solved various problems. You won't get the religious wars over what's best as much because those decisions will have been made.





So those are the issues you should bring up on the forum of your choice, but in general, your best forum will be Astromart.Where can I get advice on buying a telescope for viewing astronomical objects?
Thanks 'gn'. If I had gotten back to this question in time to choose a best answer, yours would have been my choice -- and I did put in my own vote for you. I'm glad the community voted with me.





Thanks to the others, too, especially skymaster, twogordianknots, Bruce M, and Blue.

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If you visit the UK head straight for London and locate a building called 'Telescope House'. There you will see a motley team of advanced astronomers who will give you some good tips and advice on serious astronomy. That is where I got most of my scopes from.
You might want to ask a similar question on physicsforums:


http://www.physicsforums.com/


Real astronomers/physicists/students hang out there. I don't know much about commercial telescopes, by I have a feeling you would do best to avoid those glorified novelty shops (Brookstone, Sharper Image,...). They're like airplane catalogs in store form.
Woa, hang on a minute, you want to view planets, galaxies, nebulae, comets, the moon, the sun, etc. and want to do some astrophotography with it!?.





It seems pretty obvious to me you do not have any experience in using any sort of telescope. If you are as you say a serious amatuer, then such things as a motor drive, preferably GPS, and either a built-in database of celestial objects or an interface with a computer, so that you can easily locate known objects without a lot of time and effort is the wrong approach and gonna cost you dearly.





Most serious amatuers start out with the naked eye and a good set of charts to learn the sky and progress to binoculars long before they purchase a telecope.





I suggest that you learn the fundementals before you spend up to about $4,000 which is probably not sufficient if you want to do Astrophotography as well. The best advice is to join a club where you can try them out and decide which is best for you, not to jump into the deep end straight away before you can swim.





Having said that, if what you want is to view planets, galaxies, nebulae, the aperture of the scope is most important, which will need to be at least 8-10'; this may fit in your budget, but if you want to do astrphotography proper I would reccomend a good quality 4''-5'; apochromatic refractor such as a Takahashi, Astro-Physics or similar quality make, that will cost 3-5k. The mount needs to be as good as the telescope, at a cost of about 4-5k and then you will need a guidescope, say a small WO66ED, and of course a CCD camera which will set you back another 2-3k. This will need to be supported by good software which is also expensive, not to mention a laptop computer with at least 4GB RAM and a fast hard disk.





So you see your $4k is not going to be enough. To do all the things you want to do (including all the necessary accessories) will set you back about 10k.





If I were you I would spend much more time on visual work first, before you start thinking about astrophotography, which you clearly have not considered at all in any detail.





Good luck though, and welcome to the hobby.
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The absolute best forum to discover astronomy equiptment and the hobby in general is Cloudy Nights--www.cloudynights.com . A great many extremely knowledgable amateur astronomers along with a few professionals are frequent posters. It is by far the largest such community on the web.





IMHO, If you intend to primarily do visual astronomy, you should probably consider the Celestron CPC11. If you want a better photographic rig, you need to invest heavily in the mount, sacrificing telescope size for mount performance. That is, in visual astronomy you can get away with a cheaper mount that comes as part of a package from a major manufacturer but in astrophotography you cannot.
Hi





Looks like you getting some good advice. The most important thing is to have fun with the hobby. Don鈥檛 drive yourself crazy trying to pick out the right scope because if you stay with the hobby you are going to own one of each type,refractor,reflector and SCT. Buy big enough to do the job but portable enough you will use it on a regular basis. The CPC Celestron 11 might be a little big but the CPC 9.25 might be more to your liking if it is too heavy you won鈥檛 use it. You will learn the night sky as you go along. The more you learn the more you will enjoy and the best source is your local Astronomy club. We have members that know the night sky very well and some that don鈥檛, I fall in the middle. I have always felt that there is no such thing as a selfish astronomer they are always willing to share the view and their knowledge.





For Scopes


OPT.com


Astronomics.com


Astromart


Telescope.com


Telescopes.com





Scope Reviews


Cloudynights





Astrophotography


Scopetronics





Heavens-above.com 鈥?for passes of the ISS, HST and Etc.


Skymaps.com 鈥?Monthly Sky map





When you decide you are in need of an atlas 鈥?Pocket Sky Atlas from S%26amp;T





Google Virtual Moon atlas for some free software to help with your lunar observations





Goodluck
Sounds like you want a fighter jet before you have a learner's permit for a car. You want a scope that can view every type of celestial object, and do the difficult job of astrophotography, and do the finding for you.





Get to know the sky first. How much experience do you have so far? If it's little or none, I strongly suggest finding an local amateur astronomy club. You can find out when they're having a night out, look through different scopes, and most importantly, get a realistic expectation of what you can see.

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