It’s a reflector. The only difference is the mount, which is alt/az as opposed to equitorial/Newtonian. So it can’t track objects, but it IS easier to carry around and essemble, so if you don’t mind repointing every minute or so, you can get a bigger diameter mirror for the same price and have it easier to carry.

Posted by eri, on January 25th, 2009, at 2:24 pm. #.

The Dobsonian telescope is a design that has become popular amongst amateur astronomers because it results in an extremely simple and rugged large-aperture instrument at low cost. The term “Dobsonian” or “Dob” refers to any telescope with an alt-azimuth mount and a Newtonian telescope tube assembly that feature several innovations made popular by John Dobson. The telescope is a favorite among amateur telescope makers who pioneered many of its original features and has been made increasingly popular by commercial telescope makers.

A reflecting telescope (reflector) is an optical telescope which uses a combination of curved or plane (flat) mirrors to reflect light and form an image (catoptric), rather than lenses to refract or bend light to form an image (dioptric).

Posted by myllur, on January 27th, 2009, at 11:19 am. #.

Donsonian refers to a type of mounting invented by James Dobson of San Francisco. It is basically a simplified alt-azimuth system. Great for easy pointing, but it ***** for tracking.
Reflector refers to the type of optics in the telescope. The first reflector was invented by Isaac Newton in 1673. There are several other types of reflector in use today.

Posted by tham153, on January 28th, 2009, at 3:06 am. #.

A Dobsonian telescope is a type of reflector telescope. The only difference is that a Dobsonian is mounted on a Dobsonian mount, which is a simple altazimuth mount made simply of inexpensive materials. The tube, mirror, diagonal, mirror cell, eyepiece and focus assembly are all those of any other reflector telescope. Some manufacturers offer the same reflector telescope on a Dobsonian mount or an equatorial mount of some more complex type. The Dobs is cheaper.

Posted by aviophage, on January 29th, 2009, at 6:38 pm. #.

A Dobsonian is a Newtonian reflector with an alt azimuth mount.

Posted by mr.gold, on February 1st, 2009, at 7:57 pm. #.

A Dobsonian is a reflector. More specifically, it is a newtonian reflector, however, “Dobsonian” does signify the type of base.

Some dobsonian telescopes have optical tubes that can be mounted on a german equatorial mount. These are typically enclosed tubes with the center of mass somewhere near the middle of the tube. Some, however, have truss tubes and the center of mass of the tube is at the primary mirror. These are typically mounted on cradle type dobsonian mounts and it would be impractical, if not impossible, to mount them on a tripod based german equatorial mount using traditional methods.

Posted by minuteblue, on February 3rd, 2009, at 7:33 pm. #.