Although most people think of telescopes it may be best to consider binoculars first. They are portable, convenient and relatively inexpensive. Cheap binoculars are better than a cheap telescope. Consider something like 7 x 35 binoculars. The 7 is the magnification produced by the eyepiece, the other number is the aperture in millimeters. This size is light and easy to hold.
If you are considering a telescope there are essentially three types available to the amateur astronomer.
Refractors consist of lenses at both ends, and the most recognized type of telescope. They generally cost more per aperture inch than other telescopes, but their size makes them ideal beginner telescopes. It's best to avoid cheap department store models, as these quote large magnifications but have small, useless apertures. The job of a telescope is to collect an images light, not magnify it, so large magnifications actually make things worse and can alter data. Earthly telescopes usually have extra lenses to make an image appear right side up, but this extra lense can cut down the amount of light that reaches the eye. Therefore, the extra lense is left out of astronomical telescopes, which leaves images upside down. Since lenses can create false rainbow images around really bright objects, it's best to buy a filter to help correct the problem.
The next type of telescope is called the reflector, and these are usually comfortable because of the eyepiece position. In this telescope, light reflects off mirrors as is travels down the telescope tube and through the eyepiece on the side. In order to be as useful as a refractor, the reflector must be larger in size. Although they don't create false rainbow images, the main mirror on a reflector often needs to be readjusted, and there are kits for this. A popular type of reflector is called a Dobsonian, and this is convenient because it has a mount instead of a tripod.
The final type of amateur telescope is the Schmidt-Cassegrain, and this uses lenses and mirrors to fold a light path back onto itself within a compacted tube. This telescope is usually less expensive than refractors, dearer than reflectors, and are easier to handle than both.
The specifications of a telescope may quote numbers which can affect the exposure needed if you pursue astrophotography. They will not affect the image you see; however, it's best to become familiar with the sky before you start with astrophotography.
If you join a local astronomy club, you may be able to look into the different types of instruments, or you can just check your local library. Also, reputable astronomy magazines are available for reading reviews on quality telescopes, as well as manufacturers advertising.
Purchasing the largest aperture you can find is the best idea, but don't buy a telescope larger than you can lug around. Smaller telescopes are easier to set up and more convenient to use. You also don't want to waste your money on a large telescope if atmospheric pollution is high in your area, as this will prevent the telescope from giving you its best results.
The general rule for calculating the maximum practical magnification a telescope can achieve is to double the aperture in millimeters, e.g. a 100mm aperture telescope should have a maximum magnification of 200x. So spend the majority of your budget on getting a larger aperture, not more accessories. Do not be tempted to buy an eyepiece that will allegedly stretch magnification beyond the maximum value calculated from the aperture. If given a choice of eyepieces start off simple. A Kellner is a good general-purpose eyepiece and a Barlow lens placed between a focuser and eyepiece can triple magnification.
Along with finding celestial objects, telescopes also follow the movement of those objects. The instrument must be moved repeatedly to keep the object in focus, and different mounts and drives make this possible. Electronic drives will point a telescope in the right direction, but the sturdiness of the mount is the most important thing.
It is important to realize that many textbook and telescope advertisement photos are long exposures with false colors added. Stars seen through a telescope will always look like points of light, and you will not see color in dim objects. The eye is not sensitive enough.
So, let's talk about what you will see with a beginner telescope. With just a 75mm refractor or 150mm reflector, you can see nebulae, galaxies, moon craters, Saturn's rings, and even some of Jupiter's moons. All of these are amazing objects to view as you learn about the night sky. - 15437
If you are considering a telescope there are essentially three types available to the amateur astronomer.
Refractors consist of lenses at both ends, and the most recognized type of telescope. They generally cost more per aperture inch than other telescopes, but their size makes them ideal beginner telescopes. It's best to avoid cheap department store models, as these quote large magnifications but have small, useless apertures. The job of a telescope is to collect an images light, not magnify it, so large magnifications actually make things worse and can alter data. Earthly telescopes usually have extra lenses to make an image appear right side up, but this extra lense can cut down the amount of light that reaches the eye. Therefore, the extra lense is left out of astronomical telescopes, which leaves images upside down. Since lenses can create false rainbow images around really bright objects, it's best to buy a filter to help correct the problem.
The next type of telescope is called the reflector, and these are usually comfortable because of the eyepiece position. In this telescope, light reflects off mirrors as is travels down the telescope tube and through the eyepiece on the side. In order to be as useful as a refractor, the reflector must be larger in size. Although they don't create false rainbow images, the main mirror on a reflector often needs to be readjusted, and there are kits for this. A popular type of reflector is called a Dobsonian, and this is convenient because it has a mount instead of a tripod.
The final type of amateur telescope is the Schmidt-Cassegrain, and this uses lenses and mirrors to fold a light path back onto itself within a compacted tube. This telescope is usually less expensive than refractors, dearer than reflectors, and are easier to handle than both.
The specifications of a telescope may quote numbers which can affect the exposure needed if you pursue astrophotography. They will not affect the image you see; however, it's best to become familiar with the sky before you start with astrophotography.
If you join a local astronomy club, you may be able to look into the different types of instruments, or you can just check your local library. Also, reputable astronomy magazines are available for reading reviews on quality telescopes, as well as manufacturers advertising.
Purchasing the largest aperture you can find is the best idea, but don't buy a telescope larger than you can lug around. Smaller telescopes are easier to set up and more convenient to use. You also don't want to waste your money on a large telescope if atmospheric pollution is high in your area, as this will prevent the telescope from giving you its best results.
The general rule for calculating the maximum practical magnification a telescope can achieve is to double the aperture in millimeters, e.g. a 100mm aperture telescope should have a maximum magnification of 200x. So spend the majority of your budget on getting a larger aperture, not more accessories. Do not be tempted to buy an eyepiece that will allegedly stretch magnification beyond the maximum value calculated from the aperture. If given a choice of eyepieces start off simple. A Kellner is a good general-purpose eyepiece and a Barlow lens placed between a focuser and eyepiece can triple magnification.
Along with finding celestial objects, telescopes also follow the movement of those objects. The instrument must be moved repeatedly to keep the object in focus, and different mounts and drives make this possible. Electronic drives will point a telescope in the right direction, but the sturdiness of the mount is the most important thing.
It is important to realize that many textbook and telescope advertisement photos are long exposures with false colors added. Stars seen through a telescope will always look like points of light, and you will not see color in dim objects. The eye is not sensitive enough.
So, let's talk about what you will see with a beginner telescope. With just a 75mm refractor or 150mm reflector, you can see nebulae, galaxies, moon craters, Saturn's rings, and even some of Jupiter's moons. All of these are amazing objects to view as you learn about the night sky. - 15437
About the Author:
David Wildash shares information and resources on his website about Telescopes , and you can read more about buying a telescope
