$refractor vs reflector$

$refractor vs reflector$

The ‘truss tube’ design, in particular, eliminates the need for a telescope tube the size of a hot-water heater. In the past 10-15 years, telescope makers have developed more innovative Dobsonian designs to make it easier to transport large telescopes to observing sites. Yet a quality Dobsonian scope of this size can cost less than $500. For most observers, it is not too long or heavy to move, yet it still has enough aperture to show thousands of deep-sky objects. An 8-inch (200 mm) f/6 Dobsonian with a focal length of 1200 mm is an excellent workhorse telescope, even for beginners. If you’re interested in strictly visual observing, and you want the most aperture (and light-gathering capability) for your money, a Dobsonian telescope is well worth your consideration. With huge mirrors (up to 36” in diameter) these new-age Newtonians are called “light buckets” because of their immense light-collecting ability. Dobsonians can’t be beat for purely visual deep-space observing. The “Dobsonian” telescope is just an inexpensive large-aperture Newtonian on a simple alt-azimuth mount that points left-right (in azimuth) and up-down (in altitude). Newtonians came back into style in a big way in the 1980’s when telescope makers commercialized a design by the former monk and astronomy popularizer John Dobson. Dobsonian reflector telescopes (credit: Meade Corp.) Dobsonian Reflectors Another advantage of Newtonians: because mirrors reflect all colors of visible light exactly the same, reflecting telescopes have no chromatic aberration. But it’s not a big deal if the focal ratio is bigger than f/6 or so. This makes stars appear wedge-shaped at the edge of the field of view. Newtonians also have a type of optical aberration called “coma”. Newtonians also tend to be bulky, with tube lengths of 4-5 feet or more. The adjustment is not complicated, but it takes a little practice. Newtonian reflectors occasionally require adjustment of their optical alignment– especially if the scope gets bumped. A top-of-the line 4-inch refractor costs as much, or more than, a 12-inch Newtonian reflector, yet the reflector has 9 times the light gathering capability. A smaller secondary mirror reflects light out the side to an eyepiece. The front of the tube is open the mirror sits at the back of the tube. Some homemade reflectors even use glass from the discarded portholes of a ship! The layout of a Newtonian reflector. And since no light passes through a mirror, less expensive glass is used. įor a given aperture, Newtonian reflectors are generally the least expensive telescope because, unlike the lenses of a refractor, only one surface of a mirror needs careful figuring and polishing. His immensely practical design, now called the Newtonian reflector, is the main type of purely reflecting telescope in use today by amateur astronomers. He used a second small diagonal mirror to direct light out the side of the telescope to an eyepiece.

$refractor vs reflector$

Isaac Newton gets credit for inventing the first reflecting telescope in the late 17 th century. Reflecting telescopes (or reflectors) collect light using a curved mirror at the rear of the main tube rather than a lens at the front end.

$refractor vs reflector$

In IRLP a reflector is a computer based server which connects 2 or more 'nodes' (A node is a Repeater connected to a computer or a IRLP computer connected to a radio operating simplex.) together via server to create kind of 'conference room'.A Newtonian reflector telescope on an equatorial mount (credit: Skywatcher). Wikipedia: Internet Radio Linking Project Since most reflectors have 10 channels, there are approximately 200 unique reflector channels available for use. As of April 2007, there are 20 operational reflectors (including Echo Reflector 9990, which digitally records and plays back transmissions for testing purposes). The first 3 digits consist of the reflector number, while the fourth digit represents the channel number. Each reflector has a unique 4 digit node number in the range of 9000-9999. Most reflectors on the network have 10 channels (0-9) with channel 0 being the main channel. Reflectors are a type of conferencing system. Stations wishing to communicate with 3 or more nodes at the same time may accomplish this by connecting to what is called an IRLP Reflector. IRLP connections are of two types: node to node, and node to reflector.

$refractor vs reflector$

Refractor vs reflector