* Questions to ask yourself before buying
* Important features to look for in a telescope
* Understanding telescope specification

Questions to ask yourself before buying:
There are lots of telescopes available on the market, and for the beginner, selecting one can be a bewildering experience. Before buying a telescope it is important to ask yourself the following questions:

1. What is your budget or how much do you want to spend? Generally, with optical equipment, the more you spend the better it gets. This reflects quite clearly with optical equipment because when you use it, you are truly looking through it and getting the direct result of how much you have invested. So the clarity, magnification and brightness are right there in front of you and will perform generally in accordance to your budget. My advice is to invest as much as you can within your budget. Check the links in the main menu on the home page (left side) for the 3 sections on telescopes by price range.

3. Is the telescope going to be used for dedicated Astronomical viewing? If this is the case try to get a telescope with the objective size as big as possible. In simple terms, The OBJECTIVE SIZE is the diameter of the tube of the telescope and where the light comes in. Dobsonians and Reflectors are a good example of this. With Dobsonians, comparing the cost of the telescope to the size of the tube or objective lens, it is a very economical way of getting good performance out of your telescope. Generally the tubes or objectives size start out at around 8 inches (or 200mm)in diameter and go up to 12 inch (or 250mm). So Dobsonians have heaps of grunt but the only down side is the lack of fine tune controls. You may have noticed the dials or controls on some telescopes for moving the telescope into position at the target image. These are the fine tune controls and can be quite handy in keeping what is essentially a moving object image in your sights. The lack of the controls may only be a minor inconvenience in comparison to the shear magnifying power of the Dobsonian. So if you are on a budget of around $500 up and power is your priority, check out the Dobsonians. One more note on the Dobsonian, if you can spend a few dollars more, get the new auto tracking Dobsonians which will track your target object in relation to the earths rotation. (this is not a go to)

4. Do you need something fully automatic and price is no object? In other words, "type in the destination view and take me there" The most popular solution here is a combination of a full go to mount and optical tube assembly. The EQ5 and EQ6 Pro Go To mounts combinations are the perfect solution to get you there quick, stay on target and enjoy the view. This solution can be useful for advanced astronomical photography.

If you need to have a chat with someone, check out out the Live Online Chat on the right side of the page. We are happy to assist in any way we can.

 

What kind of observing would you like to do? Astronomical, Terrestrial or both?
Selecting a telescope for both astronomy and land viewing sounds attractive, but these applications can work against each other, and your choice will usually be a compromise. However, once you have decided on the telescopes main purpose, choosing one can become much easier.
If you have decided that your telescope will be used primarily for observing the night sky, the instrument required does not necessarily need to give a right side up image and is not required to focus on nearby objects. With the exception of the moon, planets and close star clusters, interesting night sky objects are faint, in fact most are very faint. As a new observer you may be mainly interested in viewing the moon and planets, and if this is the case, a telescope with a small objective (primary mirror or lens) may be sufficient. However, most observers quickly graduate to galaxies, nebulae, globular clusters, open clusters etc. To view these objects you will require a telescope with the largest aperture that is possible for your circumstances, which will include things like cost, weight, portability, etc.

Newtonian reflector telescopes are a popular choice for astronomical use because they have the lowest cost per inch of aperture. Observation of faint deep sky objects, such as nebulae and galaxies, can be achieved at a relatively reasonable cost by reflectors having mirror diameters of 150 to 200mm (6 to 8 inches). Refractor telescopes are good for achieving high power and contrast when viewing the planets and the moon. They have a reputation of providing crisp, sharp-quality images. Since they are virtually maintenance free, they are easy to operate, but due to high costs for the large aperture scopes, most beginners will choose a Newtonian reflector as a first scope for all round astronomy. Short-tube refractors are now another low cost option for beginners. Their smaller size makes them an excellent choice for a portable telescope and the beautiful wide-field star vistas which they provide, are great for learning your way around the night sky.



 

Terrestrial viewing can easily be achieved with both short and long optical tube refractors, but shorter refractors with apertures of 70mm to 100mm, and focal lengths of 400mm to 700mm are preferred. Shorter scopes have wider fields of view than longer scopes and for land as well as night viewing, gathering more light gives better resolution which is more important than magnification. When choosing a scope for this purpose keep in mind that you will also be trying to look through the air in front of you, and at higher magnifications the image will shimmer, especially on hot, windy days. Newtonian reflectors are not suitable for terrestrial viewing because observing is done through the side of the tube and you therefore have to turn sideways to the target. Since there is no reasonable way to compensate for this, refractors make better terrestrial scopes. For dual purpose viewing, the refractor is a better choice but with larger apertures you do not have to magnify as much to achieve the same resolution. When using your refractor for daytime viewing, a 45 degree erect image diagonal is required to turn the image right side up. For night sky use, a 90 degree star diagonal is almost a necessity to avoid a strained neck.

 

Where will the telescope be used?

When astronomical viewing in urban areas, using a longer tube will increase the contrast, but it will give you a smaller field of view. If you do want to use larger aperture scopes in the city, just remember to use lower power. All telescopes will perform far better in darker sky areas.
Important considerations include convenience of use, portability, ease of storage and ease of transportation to dark sites. Short tube Catadioptric-Newtonians (Sky- Watcher 1141EQ1, 1301EQ2, and 1501EQ3-2) and short tube refractors (Sky-Watcher 705AZ3, 804AZ3, 1025AZ3) are good choices if there are any restrictions.
 

Understanding telescope specification

Aperture Diameter
The clear aperture of a telescope is the diameter of the objective lens or primary mirror specified either in inches or millimeters. The larger the aperture the more light it collects and the brighter (and better) the image will be. Greater detail and image clarity are observed as aperture increases.
Focal Length
This is the distance (usually in millimeters) of an optical system from the lens (or primary mirror) to the point where the telescope is in focus (focal point). The longer the focal length of the telescope, generally the more magnifying power it has, the larger the image and the smaller the field of view.
Focal Ratio
This is the ratio of the focal length of the telescope to its aperture in the same units of measurements. For example, the f/ratio of a telescope with a 200mm aperture and a focal length of 1000mm is: 1000 / 200 = 5, or f/5. Telescopes of f/4 to f/6 are called "fast" systems. They offer lower magnifying power and wider fields of view than slow f/8 to f/15 systems.
Magnification
The most common misunderstanding of telescopes is that they are rated by their magnifying power. The fact is, telescopes are rated by their aperture or light gathering capability. The aperture of a telescope is far more important than the magnifying power, because it determines the telescopes ability to resolve small or distant objects. See Usable Magnifications.