Meade 5x Ultra TX TeleXtender 1.25 Inch Format

Q1: I want to buy my 12 yers old a telescope for his birthday. I do not want crap. I was looking at a reflector because it can bring in alot of light and i thought that would give a good view of the planets but I read a refractor will also do this. What are t

A: In telescopes, one pretty well gets what one's willing to pay for. But that doesn't mean a refractor is better than a refractor or vice versa. Telescopes are all about gathering and focusing light, and telescopes with larger lenses or mirrors gather more light than do telescopes with smaller ones. The greater the amount of light you can gather and focus, the dimmer will be the objects that you'll be able to see. So a larger lens or mirror will enable you to see more objects and farther out into space. A reflector uses mirrors to focus light, whereas a refractor uses lenses. Mirrors are less complex and therefore less expensive to make than lenses. Thus you can get more light-gathering ability -- and see more objects -- for less money in a reflector than you can a refractor. Reflectors have disadvantages, though. One is that they are subject to "coma," which is an optical aberration that makes star pinpoints appear somewhat comet-shaped. This can be corrected to some extent with use of parabolic mirrors and a device called a "Paracorr." However, reflectors are never completely coma-free. A second disadvantage is that a reflector produces images that are upside down. This cannot be entirely corrected, though an erecting eyepiece will help somewhat by allowing you to see right side up if you align your body with the telescope's axis. A refractor, on the other hand, is not bothered by coma. However, it is subject to chromatic aberration, or color fringing around objects. This can be largely corrected through use of multiple lens elements and chemical coatings. This, however adds to the cost of the optical system, so you'll see 6-inch refractors costing considerably more than reflectors of the same aperture. That said, the sharpest lunar and planetary images are obtained with a refractor.