Be prepared to do some heavy lifting if you're interested in a large Dobsonian. The second drawback to those interested in astrophotography is that they are primarily visual telescopes. Dobsonians can offer some good planetary images with a planetary camera, but cannot be used for deep sky imaging due to their alt-az style mount.
These minor drawbacks aside, Dobsonians are hard to beat for all-around visual observing performance. Explore Dobsonian Telescopes. Best for deep sky imagers who want a long focal length scope with great optics. If you're hoping to primarily image distant galaxies or just get close-up views of deep sky objects in general, an RC may be right for you.
Unlike a Newtonian or many refractors where additional accessories are needed to begin serious imaging, RCs are some of the best out-of-the-box astrophotography telescopes. Featuring a coma-free design, RCs suffer from very few optical aberrations imperfections , making them ideal for serious imagers. Due to a large central obstruction, which is where the secondary mirror obstructs the light path, RCs tend to have lower natural contrast than other optical designs and therefore aren't as ideal for planetary imaging like Schmidt-Cassegrains are.
This also means poor visual performance, and we don't recommend buying an RC for visual use. RCs also feature slow focal ratios, which make them great for distant objects, but generally requiring longer exposure times than faster telescopes. This also means they are rather unforgiving telescopes in terms of tracking errors, and for that reason are not recommended for beginning imagers. The slow focal ratio can, however, be alleviated somewhat with the use of a reducer. Overall, RCs are limited in their use, but excel at what they're made for: imaging distant deep sky objects.
Though less common, telescopes like the Classic Cassegrain and the non-corrected Dall-Kirkham designs are excellent reflectors used primarily for high-end planetary viewing and imaging. Since these telescopes use an all-mirrored design, they are generally considered superior to other planetary telescopes like Schmidt-Cassegrains or Refractor telescopes which use glass lens elements and can introduce chromatic aberration.
Classic Cassegrains and Dall-Kirkhams do not suffer from any chromatic aberration and have very long native focal ratios, making them the ideal choice for high-end and research-grade planetary observing. Most of these telescopes are very expensive and have this specialized use, but excel at long focal length viewing and imaging.
Coma is an optical aberration which affects all Newtonian including Dobsonians telescopes. This issue is easily fixable with a coma corrector, but this extra accessory is an added cost on top of the telescope itself and can get expensive. Generally speaking, you won't need a coma corrector if you're just observing visually unless you're using a fast Newtonian or prefer excellent edge views in your eyepiece. For deep sky imaging, though, a coma corrector is usually advised, especially if you're using a large sensor camera.
Great question! Collimation is a simple process, and we're currently working on a video to best explain how to collimate your Newtonian or Dobsonian at home. You will need a collimation tool, and we recommend a laser collimator in most cases. Stay tuned! That depends on the type of reflector.
However, we don't necessarily recommend them for a beginner for a few reasons. For one, both Newtonians and RCs will need to be collimated from time to time. Second, both designs can be relatively large and heavy, which translates to needing a large and sturdy mount to support them. Lastly, RCs have a specific use case of long focal length deep sky imaging. All of that being said, both can be a great choice if you're an experienced imager and are not afraid of the challenges of more hands-on imaging.
Newton was not the only astronomer to think of building a telescope with a mirror, but he was the first to produce a working reflecting telescope. His telescope was shown to the Royal Society of London , one of the most distinguished organizations promoting science. The demonstration was so successful that Newton was elected to membership to the Royal Society immediately. Reflecting telescopes proved difficult to construct. The mirrors were hard to polish to the proper shape. A parabolic mirror is able to focus all of the light to one point and thus provides a crisper image than does a spherical mirror.
I know about this parabolic shape, as it is the design my brother used in making his own telescopes. At Orion, we are committed to sharing our knowledge and passion for astronomy and astrophotography with the amateur astronomy community. Visit the Orion Community Center for in-depth information on telescopes , binoculars , and astrophotography.
You can find astrophotography "how to" tips and share your best astronomy pictures here. Cart 0. Order Status Help Community All Current Offers.
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