Astronomy is a hobby practiced by many throughout the world, though with varying levels of success depending on where they live, their budgets and general dedication to the pastime. Fortunately, there are some basic tips to keep in mind when purchasing the equipment, allowing for a better experience. Here's variations of optical telescopes and what to look for when buying one.
Refractors
One of the most common forms of telescope, refractors are traditional and easy to use. They use a larger objective lens and an eyepiece to gather plenty of light, more than the human eye is capable of. This creates a magnified and focused image for the user to see.
Due to the simple mechanics of the refractor, these are often cheaper than their counterparts and are favored because of this. Furthermore, they're easy to use, reliable and have a moderate level of clarity. That said, it does have its downfalls, especially in the form of distortions in the image.
There are also a number of problems in the image, such as chromatic and spherical aberrations. While this is reduced in longer focal lengths, it is still present, as is color fringing. Bubbles trapped within the glass can also cause distortions while viewing and result in an overall diminished viewing experience.
Reflectors
Using a curved mirror as its primary reflective surface, these telescopes can create an image on the focal plane. The focal length is the distance between the mirror and the focal plane and recording equipment can be placed here to record the image. For real-time visual observation, a second mirror can be placed here. One of the main reasons for using a reflector telescope is to view large diameter objects.
While the low-tier reflectors suffer from many of the aberrations of other telescopes, minus the chromatic aberration which it does not suffer from, it can be fitted with correction lenses to reduce such problems. However, it should be of note that reflectors are already more costly than refractors and correction lenses only increase these costs further. The upside is much better image quality, especially with correction.
Catadioptric
Catadioptric systems use a combination of both reflectors and refractors both implemented in a spherical shape. This creates a wider field of view and further reduces the aberrations present in its counterparts. However, it is much more costly than both refractor and reflector types.
The catadioptric telescope is known for its portability and quick set up times, making it excellent for stargazers wishing to drive to the edge of town looking for a clear patch of sky to look to. They can be excellent investments and while image quality is important, usage is what will really reveal the best telescope at the end of the day. One that sits in the attic for years, but has excellent resolution will lose to one that you can carry where you want and use every day, even though its image quality is lacking.
That's the three main types of telescope and their pros and cons. Refractors are the cheapest and provide a moderately good image, while reflectors cost more, but provide an excellent image. Catadioptric systems are the most expensive, yet very portable and have a decent image. These are the optical telescopes and what to look for when buying one.
Refractors
One of the most common forms of telescope, refractors are traditional and easy to use. They use a larger objective lens and an eyepiece to gather plenty of light, more than the human eye is capable of. This creates a magnified and focused image for the user to see.
Due to the simple mechanics of the refractor, these are often cheaper than their counterparts and are favored because of this. Furthermore, they're easy to use, reliable and have a moderate level of clarity. That said, it does have its downfalls, especially in the form of distortions in the image.
There are also a number of problems in the image, such as chromatic and spherical aberrations. While this is reduced in longer focal lengths, it is still present, as is color fringing. Bubbles trapped within the glass can also cause distortions while viewing and result in an overall diminished viewing experience.
Reflectors
Using a curved mirror as its primary reflective surface, these telescopes can create an image on the focal plane. The focal length is the distance between the mirror and the focal plane and recording equipment can be placed here to record the image. For real-time visual observation, a second mirror can be placed here. One of the main reasons for using a reflector telescope is to view large diameter objects.
While the low-tier reflectors suffer from many of the aberrations of other telescopes, minus the chromatic aberration which it does not suffer from, it can be fitted with correction lenses to reduce such problems. However, it should be of note that reflectors are already more costly than refractors and correction lenses only increase these costs further. The upside is much better image quality, especially with correction.
Catadioptric
Catadioptric systems use a combination of both reflectors and refractors both implemented in a spherical shape. This creates a wider field of view and further reduces the aberrations present in its counterparts. However, it is much more costly than both refractor and reflector types.
The catadioptric telescope is known for its portability and quick set up times, making it excellent for stargazers wishing to drive to the edge of town looking for a clear patch of sky to look to. They can be excellent investments and while image quality is important, usage is what will really reveal the best telescope at the end of the day. One that sits in the attic for years, but has excellent resolution will lose to one that you can carry where you want and use every day, even though its image quality is lacking.
That's the three main types of telescope and their pros and cons. Refractors are the cheapest and provide a moderately good image, while reflectors cost more, but provide an excellent image. Catadioptric systems are the most expensive, yet very portable and have a decent image. These are the optical telescopes and what to look for when buying one.
About the Author:
Sneak a peek at our article for the inside scoop on what to look for when purchasing a Optical Telescope. You will also get complete details on how and where to find affordable Used Optical Telescopes on the Internet.
No comments:
Post a Comment