Astronomy Telescopes
Space Telescopes
Welcome to The World's Best Astronomy Telescopes.
Whether you are a beginner, amateur or professional, you'll find telescopes priced for every budget and every level of experience.
Our selection includes Celestron Telescopes, Meade, Orion, Bushnell, Vixen, Tasco and other brand names. From tabletop decorative home telescopes to pro-grade telescopes for deep space exploration and telescope accessories, you'll find everything you need here.

TYPES OF TELESCOPES

There are 3 main types of telescopes for professional and amateur use.
These are called Optical Telescopes and are used for both terrestrial and celestial viewing.
Your choices are:

1. Refractor telescopes which use lenses to magnify any visible light.

2. Reflector telescopes which use curved mirrors to focus light.

3. Catadioptric telescopes are telescopes that are a mix of both systems, lenses and mirrors.

For example: One of the most famous reflector (reflecting) telescopes, is the Hubble Telescope. It is a Cassegrain-type reflector and works by reflecting light from a primary mirror to a secondary mirror and then focusing that light through a hole in the center of the primary mirror towards the Hubble's instrumentation to resolve the image and send it to earth.

Contrary to the belief that magnification is the key to a telescope's real power, it is really in it's ability to collect more light than the human eye. This is accomplished by the size of the mirror. The bigger the mirror, the more light is captured and then, magnified by the eyepiece.hubble telescope diagram

The Hubble telescope, is currently wandering space and has an unobstructed view in which to gather light and produce exceptional images of the most distant planets, stars and galaxies.
(image from NASA and STScI)




Which is Better - Refractor Telescopes, Reflective Telescopes or Catadioptric Telescopes?

Before we look at the pros and cons of different telescope types, it is important to address the issue of magnification. Many telescopes boast of 400x magnification or 600x magnification. This magnification is attributed to accessory lenses and eyepieces which do the major amount of work after receiving the initial image and then further magnifying it.

Magnification is fine, but often, there is a price to pay in the quality of image obtained. Yes, there is more image, but the clarity is what suffers. It is therefore advisable to consider the aperture size rather than magnification. By aperture, we mean the actual size of the light gathering lenses or mirrors. Here is where the light is received. The more light captured, the better the viewing experience.

Now, if aperture size is so important, does that mean one should buy the biggest available? Not so fast... It just may not be a practical decision to lug around a super heavy telescope especially if you plan on escaping the city lights and heading out to the countryside for better viewing.

The fact is, some telescopes can get quite heavy. Add to that the time it takes to set up, and it can be a less than enjoyable experience. Make sure you buy something that won't be gathering dust just because it's just too much effort to set up. Clearly - easy handling is a key issue for any star-trekker...



Refractor Telescope: Your garden variety, everyday telescope using lenses.

Pros
- Great viewing experience for gazing at the moon, planets and stars.
- Simple design makes it easy to use and reliable.
- Excellent Terrestrial viewing.
- Usually little or no maintenance required because of permanently mounted and aligned lenses
- Reduced image degradation because of sealed tube structure.
- Images are not obstructed by secondary mirrors.
- Good color rendering of images.

Cons
- Lens production is more expensive than a reflector or catadioptric telescope.
- Viewing faint objects in deeper space is more difficult because of aperture limitations.
- They are typically bulkier and heavier than reflectors and catadioptric telescopes of same aperture size.
- Higher lens cost and bulkiness might dissuade a buyer from the purchase of a more practical (larger-sized) aperture telescope.





Reflector Telescope:


Uses a concave mirror to reflect the image to a secondary mirror and then to an eyepiece.

Pros
- Costs less than refractor and catadioptric telescopes because the cost of manufacturing the mirrors is less than manufacturing lenses.
- Compact size makes it more portable.
- Larger aperture sizes allow better viewing of distant galaxies & stars.
- Less distortion with a brighter image delivery.

Cons
- Not the preferred telescope for terrestrial use.
- Use of a second mirror adds a slight amount of light loss.






Catadioptric Telescopes
:
Using both mirrors and lenses to capture and display an image, Catadioptric telescopes are really the best of both worlds.

Two design choices are available each with their own advantages and disadvantages. These are: the Schmidt-Cassegrain design and the Maksutov-Cassegrain design.


Schmidt-Cassegrain
Pros: - Best all-purpose telescope design, combining the optical advantages of both lenses and mirrors.

Outstanding, sharp images.
- Terrific for viewing and photographing.
- Terrestrial viewing and photography is excellent.
- Compact size makes this very portable, easy to handle.
- Very durable with a maintenance-free structure.
- Large apertures are available at very good prices.
- Excellent near-view capability.

Schmidt-Cassegrain
Cons:

- Costs more than a reflector telescope.
- Second mirror creates a slight light loss.

Maksutov-Cassegrain
The pros and cons of this telescope are much like the Schmidt-Cassegrain telescope with basically 2 differences. On the Pro side, the second mirror is smaller causing less obstruction of light entering and reflecting off the primary mirror thus offering a slightly sharper viewing experience.

On the con side, it is heavier than the Schmidt-Cassegrain.



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