TRG – Telescope Review Guide

Orion SkyView Pro 127 GoTo Mak-Cass Telescope
Here’s a telescope for the enthusiast who appreciates the practicality of a compact scope, yet wants the best features and performance available for the money. The Orion SkyView Pro 127 GoTo Mak-Cass Telescope comes with fully motorized GoTo computer control! After a simple alignment, a push of a button or two on the GoTo hand controller automatically points the telescope to one of 13,400+ celestial objects in its database. Dual stepper motors on the mount slew the telescope at a brisk 3.4° per second, centering your target right in the eyepiece. Easy!

The GoTo system consists of a computerized hand controller and two stepper motors that attach to the SkyView Pro telescope mount. What can you see with your Orion SkyView Pro 127 telescope? With intuitive menus and easy-to-use pushbutton controls, the GoTo system allows you to locate and track any object in its database of 13,400+ celestial objects including the entire Messier and NGC catalogs. You can use the GoTo controller to take a guided tour of the night sky or to pinpoint celestial highlights for the month. The GoTo hand controller requires an external 12-volt power source.

The SkyView Pro (SVP) 127’s high-resolution 5″ optics and 1540mm focal length (f/12.1) excel for high-magnification study of the lunar surface and planets. And it’s got enough aperture to display excellent astroimages of a wide variety of deep-sky jewels. The optical tube assembly is just 14.5″ long, making it wonderfully portable and easy to stow.

The Orion SkyView Pro 127 EQ mount provides fluid motion and a solid stance. 

If you are new to astronomy and aren’t familiar with where things are in the sky, then this is the best telescope for you! And the best part? You get to show others just how much of an astronomy expert you are when you can tell them the name of the object being viewed!

Catadioptric telescope

Catadioptric telescopes use a combination of mirrors and lenses to fold the optics and form an image.  There are two popular designs, the Schmidt-Cassegrain and the Maksutov-Cassegrain.

In the Schmidt-Cassegrain, light enters through a thin aspheric Schmidt correcting lens, then strikes the spherical primary mirror and is reflected back up the tube to be intercepted by a small secondary mirror. The mirror then reflects the light out the back of the instrument where the image is formed at the eyepiece.

Advantages

ﾷ Most versatile type of telescope
ﾷ Best near focus capability of any type telescope
ﾷ First-rate for deep sky observing or astrophotography with fast film cameras or CCD’s
ﾷ Excellent for lunar, planetary and binary star observing plus terrestrial viewing and photography
ﾷ Closed tube design reduces image degrading air currents
ﾷ Compact and durable

Disadvantages

ﾷ More expensive than reflectors of equal aperture
ﾷ Slight light loss due to secondary mirror obstruction compared to refractors
The Maksutov-Cassegrain telescope design has basically the same advantages and disadvantages as the Schmidt. It uses a thick meniscus-correcting lens with a strong curvature and a secondary mirror that is usually an aluminized spot on the corrector. The Maksutov secondary mirror is typically smaller than the Schmidt’s giving it slightly better resolution for planetary observing.

However, the Maksutov is heavier than the Schmidt and because of the thick correcting lens, it takes a long time to reach thermal stability at night in larger apertures. The Maksutov optical design typically is easier to make but requires more material for the corrector lens than the Schmidt Cassegrain.