How Do Telescopes Work - Telescope Lenses

Lenses and mirrors are the elements used to collect and view focused light in telescopes. Mirrors are the medium for focusing in reflector telescopes, while lenses are the medium in refractors. Each type has its own distinct advantages and disadvantages. Refractor type telescopes use lenses. These lenses bend the light when it enters the telescope from the distant object being viewed through it. Because of this refraction it is possible to closely view a distant object. The telescope has two lenses, with one slightly larger.
The eyepiece in the telescope is generally a small lens. Some telescope however, may not use lenses for the eyepiece at all. The eyepiece, in any case, is the most important element of a telescope. It is the element which lets you see correctly whatever it is that you want to focus on. These eyepieces are adjustable and are of a low power. Adjusting the eyepiece allows you to change the magnification factor. What kind of lens you use for the eyepiece is a personal choice. In today's age, several different kinds of eyepieces are available in the market. Because of this motley available, choosing the correct eyepiece fro your requirement may be a difficult task. As a result, you should concentrate on defining the criteria you think are important for your choice. The depth of field, optical quality, sharpness, clarity, brightness, market price, barrel size and how it affects your eyesight are some of the major points of concern. However these criteria always remain individual prerogatives.
Lens designs used in older telescopes go by the name of Huygens and Ramsden. Professional astronomers are advised to not use these lenses anymore as they are not of superior quality, even though they are comparatively less expensive than other market lenses. These lenses also do not provide correction for chromatic aberration or the light circles that form around brighter objects when they are viewed.
Professional astronomers use orthoscopic lenses that are designed specifically for professional stargazing. Even amateurs will find these lenses good for their telescopes. The orthoscopic telescopes use four lenses in the eyepiece, and have a 45 degree field of vision (FOV). Since the eyepiece is the element most important to the quality of a telescope, this design is a winner. The lenses do not strain the user's eyes, and can be used even for viewing closer objects like planets.
For a person with a moderate budget, a Barlow lens is a viable option. The design provides average quality but is a good bargain. It does not burn a hole in one's pocket, and yet is not of inferior quality because of its cost. The range at which this lens is available starts at a low $30 and goes up to $70. The magnification factor is generally not enough for professional use, however for amateurs it should be enough. For hobbyists, it is an ideal lens.
When you're looking for lenses for a telescope, it is important that you determine criteria that most comprehensively fulfill your needs from the lens. Adjustable lenses is a good option as it means you can view objects which are not too far, as well as distant stars with it, and thus obtain the best deal your money can buy you.
Download free hubble image space telescope as well as learning more about refractor vs reflector telescopes when you visit http://www.howdotelescopeswork.com/, the online portal for free resource on telescopes making and usage
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Antique Military Telescopes Old Sailor Sights

Antique military telescopes are available to you as replicas, through several Web sites.
At these replica sites for antique military telescopes you can purchase great replicas of antique military telescopes that were used on ships and other military vehicles. You might find, for instance huge antique military telescopes that were used as port masters or small ones that were used as spyglasses. In most cases, these replicas of antique military telescopes are not only attractive keepsakes but working telescopes as well.
The $44 spyglass telescope, for example, has a fine finish and a classic look. It is tiny enough to fit inside your pocket but when you unfold it it stretches to 14 inches. This smallest of the antique military telescopes has great optics. Its rosewood covering gives it an attractive look as well as comfortable grip. The lens on this spyglass telescope is protected from damage by a cap made of brass.
At the other end of the size spectrum of these antique military telescopes is the Port Master Telescope. Its cost is $385.
It's massive (40 inches) but attractive, and stands on a gorgeous rosewood tripod. This antique military telescope is so tall that a taller than average adult can still view through it while standing.
The Port Master has a targeting telescope that expands and contracts and is mounted on top of its main tube. Once you have honed in on your celestial (or in this case naval) target, you'll find a sharp clear image of even distant objects. The telescope's positioning instruments bring you very exacting information about your target's angle and its locking screws, which are adjustable, let this antique military telescope move easily. In contrast, it can also lock it in place.
The Port Master telescope weighs more than twenty pounds.
Anne Noonan makes it quick and easy to find the best telescope. Read expert information here.
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Three Types of Telescopes - What are the Advantages

Refractors, Newtonian reflectors and Catadioptrics are the three main types of telescopes. All these different types have the same purpose, but each telescope design does it differently. Collecting light and bringing it to point of focus so it can be magnified and examined with an eyepiece is their goal.

Of the different types of telescopes the refractor is the telescope most people think of when they think of astronomy. This type of astronomy telescope is easy to use and reliable due to the simplicity of design. It requires little or no maintenance. Its great for looking at the different types of lunar, planetary, and binary stars.

Newtonians are a type of telescope, which is also known as catoptrics. This type is different from the other telescopes because it has the lowest per inch of aperture compared to refractors and Catadioptrics, because lenses are more expensive to produce than mirrors, especially in medium to large apertures. Newtonians deliver very bright images and are low in optical aberrations.
Catadoptric telescopes are the most popular type of instrument, with the most modern design, marketed throughout the world in 3 1/2 and larger apertures. Its very good for looking at different planetary, lunar, and binary stars. If you like to take photos with your telescope this type of instrument is excellent for deep sky observing or astrophotography with fast films or CCD's.

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Jeremy Hier is the Business Manager and Webmaster of Best Telescope Guides Jeremy Hier is a freelance writer and regular contributer He likes to offer his advice and tips to consumers looking to purchase meade telescopes and celestron telescopes
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How To Use Your Telescope To Bring The Unseen Into View

Telescopes can help you to see far off objects. The distance is determined by the type and quality of your telescope. Of course, a toy store telescope will not be able to put into view the same objects as the Hubble Telescope can. Somewhere in the middle is a modest, but good-working telescope for the amateur astronomer.
To see how this viewing tool works, you must understand something about the eye, particularly about the retina. There will always be things you cannot see from far away. You must ask yourself why you cannot see them. There are two main reasons.
One reason you have trouble seeing objects that are far from you is that not enough light from the object reaches your eye. When the item is shrouded in darkness, it is hard to make out. The other reason is that the object takes up so little space on your retina that it is impossible to get a clear picture of it.
Therefore, the goals of the telescope are to focus more light on the retina, and to make a larger image of the object strike the retina. That way, it will stand out in a way that will let you examine the item clearly. Two main types of telescopes have been made to accomplish these purposes.
The refractor telescope is one type, and it uses an objective lens. The other type is a reflector telescope, which uses a primary mirror. In either case, the lens or mirror brings together plenty of light from the faraway object you are trying to study. It further focuses that light and the image it creates into a sharp point.
That is just one part of the process. If that was all that the telescope did, you would not be able to see anything more than a piercing stream of light. However, an eyepiece lens will solve this problem by magnifying this point of light. It will then be spread out over a much larger portion of the retina than it originally had been. This is how the image goes from being difficult to spot to seeming big enough to study easily.
There are a couple of properties that a telescope has that can help you see into the distance. The aperture is one. This is the diameter of the lens or mirror. A lens or mirror with a larger aperture is likely to gather more light and give you a brighter, clearer image.
Magnification allows the telescope to take the focused image and enlarge it. You can use different eyepieces on any telescope to get more or less powerful magnification. This gives you the freedom to change your telescope to suit your needs. At the same time, it does not affect the basic usefulness of your telescope.
By knowing how a telescope works, you can be aware of what parts might need to be replaced on your telescope if the time comes. You can also make it a part of your study to learn the wonders of man's explorations of the night sky.
Gregg Hall is an author living with his 18 year old son in Jensen Beach, Florida. Find more about astronomy as well as telescopes at http://www.nsearch.com/
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What Are Telescopes?

Telescopes act as windows to the universe. It is with the help of telescopes that we can study the solar system and view the conjunctions of stars. Not just that, the various planets, galaxies, satellites and asteroids that we get to see only in the books and magazines are made more familiar to us via the telescopes. They act as barrier- breaking instruments between the human beings and the outer space. The universe is no more a mystery to us that exists beyond our reach and we owe it all to the telescopes.
The modern day telescopes bring with them a wide array of accessories and it is with the aid of these accessories that it becomes much more easier to successfully put the telescopes into proper use. Let us see what are the important accessories that go well and are a “must-have” for most telescope users: -
Filters- These are very essential for telescope users because they reduce the glare on the eyepiece and scatter the light thereby making it less strenuous for us to view distant objects.
Eyepiece- this is a very important piece of equipment and its absence can render a telescope useless. Eyepieces come in a variety of sizes and if you add more than one eyepiece to your telescopes then you can have the pleasure of viewing even the tiniest and distant objects with clarity.
Mounts- Mounts are the stands for telescopes. It is a mount on which the telescope rests. Since a telescope wont function favorably in vibrations therefore you should ensure that it is placed on a stable mount.
Barlow lens- A Barlow lens helps in the magnification of telescopes. These lenses are available in different sizes and we must be careful in choosing the size that best fits the eyepiece.
There are two main types of telescopes, the refractor (Galileo) telescopes and the reflector (Newton) telescopes. The refractor telescope uses an objective lens that bends the light towards the eyepiece. While the reflector telescope uses a mirror, which collects the light and then directs it towards the eyepiece.
Though both the refractors as well as the reflector telescopes are easily available in the market we should take the following points into consideration before buying a telescope.
Do not get impressed by the magnification of the telescopes. This is because magnification alone is of no use if it just produces large but hazy images.
Aperture- This is the most important factor while deciding on a telescope. Aperture is the opening that collects light so its important to choose a telescope with a larger aperture that will ensure a clearer and a more detailed image quality.
Resolution- This enables the telescopes to produce a more detailed image. So always opt for a telescope, which has a higher resolution. Moreover since resolution is also determined by the aperture, therefore the larger the aperture the better the resolution.
Focal length- The distance between the optical center of the lens or the mirror and the optical center of the eyepiece is known as the focal length. The focal length is what determines the magnification in telescopes. Larger focal lengths imply more magnification.
If we are careful about remembering the above points then it wont take us long to choose a telescope the next time we want to buy one for ourselves.
Lisa Sparillo for http://www.telescope-information.com/.
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How To Choose The Right Telescope For Your Astronomy Interests

If there were one kind of telescope that was the only kind of telescope worth getting, there would be no market for any others. Yet, there are many different kinds being sold. This leads to the fact that not all are right for all people. When you are shopping for a telescope, it is wise to consider your particular needs.
The first thing to think about is what you want to look at. For example, the moon is seen best with certain refractor telescopes. Bird watching is also a good hobby for those with refractor telescope. However, if you want to do explorations into the deep sky, refractors are not a good choice.
A Newtonian reflector telescope is a good general telescope, but you would not have much luck using it in daytime situations. The best one for deep sky observation is the 6"-25" reflector telescope. It is not a good overall telescope, though, and it does not work well for daytime viewing.
One of the best general telescopes is the compound telescope, which uses both lenses and mirrors. It is also good for astrophotography. If you want to record your celestial finds for posterity, taking photos of them just makes sense. Many of the sights you see will never come around again in your lifetime, if ever. Take a picture of the object in the sky and you can share it with your grandkids someday.
There are also accessories that can help you use your telescope for just the purpose you choose. A star diagonal can help you look at an object that is high in the sky without making you hold your body and neck in an uncomfortable position. An erecting prism can bring images right side up if you are looking at daytime objects such as birds.
Another point to consider is where you will be when you view the sky. If you are in the city, you will be faced with overcoming light pollution. Without a dark place to observe from, you need the best telescope for the job. Compound telescopes and refractors are the best. If you have a reflector telescope, it will be overwhelmed by the urban light.
If you live in the suburbs, your landscape is probably somewhat polluted with lights, but less so than in the city. This moderate light can accommodate all types of telescopes equally well. In this case, use other means of deciding which telescope to choose.
If you live out in the country, the skies can get very dark. It would seem that this is a good thing when looking at the night sky. Refractors sometimes do not gather enough light for you to see the objects you want to see, though. Compound and reflectors bring the light into your telescope where you want it.
If you want to choose the best telescope for you, it is important to understand what the options are. You also have to go into it with an idea of what your needs are when it comes to using a telescope. Knowing these two things can help you get one you can enjoy for years.
Gregg Hall is an author living with his 18 year old son in Jensen Beach, Florida. Find more about astronomy as well as telescopes at http://www.nsearch.com/
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Buying a Telescope?

What an experience you have ahead of you if you are choosing a telescope to look at the night sky!
But even if you want a telescope for other purposes, it is important to gather a few facts about telescopes first so you know what to look for when you buy.
Types of telescope
Essentially there are two types of telescope:
A refractor telescope – that’s the ‘traditional’ type of telescope which has a lens at the front, a tube for the body, and an eyepiece at the other end.
A reflector telescope – which has an open end and a mirror at the other which directs the image to another mirror and then directs that to the eyepieceWhich should you go for?
Well, if price is important, then generally speaking you will get better ‘value for money’ with a reflector telescope. But purists will claim that you will get a better quality image with a refractor. So, if you can, try each out and make your decision.
Buying tips
DON’T be sold on magnification! Ads and salesmen will talk about so many hundred times magnification. That’s not the most important factor at all – too much magnification often only succeeds in giving you a more blurred image!
What counts is the amount of light collected by the telescope – and that depends on the size of the lens or the mirror (as a rule of thumb, multiply the diameter of the objective by 2.5, and you’ll get an idea of the magnification possible).
And don’t skimp on the tripod and mountings; make sure they are solid and steady. When you are looking at a distant object at high magnification, a wobbly tripod is not something that you want!
If you can afford it:
Go for a GoTo telescope. What’s that? Well you align it with several known objects in the sky, and then you can find just about anything else with a supplied remote control – saves hours of time and frustration.
Or go one step further and invest in a GPS telescope – using the same principle of satellite navigation used in cars, this will find any known object in the night sky for you!
Final word of warning
DON’T under any circumstances, point your telescope at the sun – ever. The damage you can inflict on your sight is unbelievable. Do not be tempted – just don’t do it!
Happy viewing.
For an essential FREE guide getting the right telescope at the right price, visit www.info4u-services.com/telescope
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A Beginner's Guide to Telescopes

For a backyard astronomer you have many options on what type of telescope to use in your endeavor. With all types of pricing, you may decide to go cheap on your first telescope, which is not advised. A cheap telescope may hinder you enjoyment of star gazing. Telescopes come in a wide variety of prices, starting with the cheap knockoffs, to the professional models that may cost thousands of dollars. If you are a beginner, you may first want to do some research to find the right starter telescope that fits your needs and budget, you should be able to find a decent starter telescope for just a few hundred dollars.
The telescopes we are going to concentrate on are Reflector, Refractor, and the Schmidt-Cassegrain class. Descriptions of each follow below.
Refractor Telescopes
The first telescope a beginner may think of are reflectors. That is the style that we are most accustomed to seeing, and cheap ones can be found plentiful in department and discount stores. But with a quality refractor telescope, This is where the comparison ends. A refractor telescope is usually a long, thin tube, mounted on a tripod. Because of this design, Refractor telescopes are portable and easy to move, and are simple to use. Refractor telescope are generally used for viewing the moon, sun, and planets.
The aperture of a refractor telescope is an important consideration for optimum viewing. This is the light gathering lens diameter. Generally, you would want have an aperture of 70mm, but you may prefer a larger diameter for a larger view.
Reflector Telescopes
If you are interested in viewing far away galaxies, distant star clusters or nebula, theReflector Telescopeis the one for you. Reflectorsuse mirrors in the base of large tubes for gathering light. An addition of a mount, or Dobsonian moves up and down to adjust for altitude, and it also pivots, a very easy design to use.
6" and 8" are popular sizes, but larger sizes are available. Price per inch, reflector telescopes are an inexpensive option for viewing deep sky objects.
Schmidt-Cassegrain
A telescope that brings together the technologies of both reflector and refractor telescopes is called a Schmidt-Cassegraintelescope.
These are the telescopes that you would use in astrophotography. A camera can be easily mounted to the eyepiece allowing breathtaking shots of the cosmos. Use of a computer and software allows you to program objects and coordinates for easy viewing. The Schmidt-Cassegrain pricing is about midway between refractor and reflector.
Angelo Valenti
This guide is designed to help the beginner astronomer make the right decision on what type of telescope may serve there needs. We make no claims to the superiority of any brand of telescope. For more information, telescopes and accessories, please visit http://telescopefanatic.com
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