Newtonian Reflector I have a 13" Reflector "Newtonian"~ are they hard to Collimate?
I am thinking about replacing ot with a Schidmts Cassegrain~ but not quite yet!
Newtonian telescopes are especially easy to collimate, since there is only one curved mirror and an eyepiece. Basically, you need to get the eyepiece centered in the image formed by the mirror, you have to get it pointed in the right direction, and you have to get it focussed.
This time-saving cooling system features three fans which have been custom designed to fit the Orion XX14g GoTo Dobsonian primary mirror cell. All three small fans work in tandem to help reduce the amount of time needed for the telescope to reach thermal equilibrium with the ambient air temperature of your observing location...
This remarkable scope combines powerful 254mm-diameter reflector optics with point-and-view simplicity in one nicely portable package. And with included Computerized Object Locator, even the first-time stargazer can pinpoint the location of 14,000+ celestial wonders stored in the IntelliScope's databank...
Orion StarBlast 4.5 Astro Reflector TelescopeLaunch a lifetime of stargazing with this compact, ready-to-use telescopeTop-notch optics show you the moon, the planets, the stars and moreScope comes fully assembled so you can go from box to backyard in minutesHigh-quality optics, point-and-view ease of use, remarkable portability, all for less than $200Your ticket to space-tourism without the zero-G nauseaMaybe it's because many of us started out with those frustrating little department store refractors, but at Orion we strive to offer quality telescopes for beginners that are easy to use and will inspire their natural inclination to explore...
Orion's SkyQuest XT8i Intelliscope Dobsonian Computerized Telescope combines powerful 203mm-diameter reflector optics with point-and-view simplicity in a nicely portable package. With the included IntelliScope Computerized Object Locator, the amateur stargazer can pinpoint the location of 14,000+ celestial wonders stored in the IntelliScope's databank...
This GPS receiver downloads precise location and time/date information to the GoTo computer on Atlas EQ-G, Sirius EQ-G, and SkyView Pro GoTo hand controllers, so you don't have to. It uses satellite global positioning data to make inputting accurate geographical location and time a breeze...
The easiest way to aim a telescope. The view seen through the window of the Telrad is continuous with the sky around it, not magnified or upside down. Three rings are lighted and appear to lie among the stars...
Orion(r) SkyQuest(TM) XT Classic Dobsonians It's no wonder customers heap 5-star ratings on these gentle giants. For not only do their jumbo-sized optics and uncomplicated design bring a "new level of joy to simple observing," raved Astronomy magazine, but they're also the most affordable quality Dobs on the market...
With a tube length of 11 inches, a 90mm (3.5") precision-polished fully multi-coated meniscus front lens, and solid uncompromising construction. the Apex 90 Compact Mak is a paragon of portability, optical excellence, and durability...
In 1609, world-renowned Italian scientist, Galileo Galilei, introduced an elementary telescope to the growing astronomy community, which sparked interest into the mysterious night sky for centuries to come...
A powerful and capable telescope, the Orion SkyQuest XT8 Classic Dobsonian is one of our most popular reflectors due to its elegant combination of precision optics, mechanical simplicity, and rock-solid stability...
I've written a book on how to build a telescope just like the one I did so anyone can do it. Every step and every piece is covered in great detail so you can actually build a powerful telescope much more powerful than the one's typically found in department stores...
In the 1960's, American amateur astronomer, John Dobson, designed a revolutionary kind of astronomical telescope featuring a lightweight large-aperture reflecting system on a simple mounting, using the then-revolutionary material called teflon...
Telescopes Aperture What kind of aperture would I need to see the Andromeda Galaxy? ?
I have a 6 inch telescope but I cannot see spiral arms.
the spiral arms in m31 are easy to photograph but need a huge telescope to see. i have an 18" and it's not a great target. the main dust lane, however, is easy.
go with geoff's suggestion and try m51 instead. it shows much better spiral structure, though it's not a great time of year for it unless you go out in the wee hours of the morning. larry454 is right too: there are more satisfying targets out there anyway. you will remember your first telescopic view of the orion nebula.
Aperture-price relation for main sequence telescopes?
We all know that given equal quality of optics and design, the amount of light gathered by a telescope is proportional to the square of the aperture diameter. But what about the typical price of the telescope? What power do you have to raise the aperture to, in order to estimate the telescope's cost?
I probably can't afford any Type "Oh!" telescopes. And I'm sort of wondering about Type "Gee."
Parabolic primary mirrors seem to be priced roughly proportional to (aperture in inches)^3, at least at larger, non-mass-produced sizes. In pounds sterling the figure you get generally isn't that far from the actual price if we are talking about good quality mirrors, but obviously you need a constant of proportionality for other currencies.
In general there isn't a good formula for calculating price vs aperture, though, since there are so many variables. Even for parabolic mirrors, faster focal ratios tend to be more expensive since there is more glass to grind out. Larger scopes frequently have faster focal ratios to keep the size of the scope remotely manageable. A 26" f/8 primary has a 17' focal length. A f/4 mirror of the same aperture is half that.
Telescopes Optics I might get a D=114 mm, F=500 mm Coated optics Tasco telescope. Will I be able to see distant galaxies?
Or is this pretty lowtech and ill only see the moon?
Any telescope will show you distant galaxies. In fact, you don't even need a telescope; you can see distant galaxies with your naked eye. However a 114mm Tasco would be a very poor choice for a first telescope. First, Tasco is a very low quality brand. Secondly, 114mm is really too small an aperture to see much of interest; you need at least 150mm, but 200 or 250mm would be better. Thirdly, a short focal length like 500mm will only give you low magnification views. I'd recommend a 150mm aperture with a 1200mm focal length as a minimum.
Here are a few web pages with good information on beginner's telescopes:
Buy from a store which specializes in telescopes and astronomy, either locally or online; don't buy from department stores, discount stores or eBay as mostly what they sell is junk. Find your local astronomy club and try out different telescopes at one of their star parties:
