BUYING A TELESCOPE

I wrote this article in 2012 when StarsbyNight was just a passionate project that Karen (founder of SBN) would brainstorm with me on how to make her passion into a reality. We were both uber excited and it was a massive learning curve, even in buying equipment. After the years have passed we know a lot more and technology and equipment and brands  are evolving but the theory and idea behind buying your first telescope still apply. 

I just want to add , just like buying a new camera lens, that the most important characteristic of a telescope is its aperture — the diameter of its light-gathering lens or mirror, often called the objective. Look for the telescope's specifications near its focuser, at the front of the tube, or on the box. The aperture's diameter (D) will be expressed either in millimeters.  Your telescope should have at least 2.8 inches (70 mm) aperture — and preferably more.

The little bit I know about buying a telescope - 21/12/2012

Let me start by saying I am no expert. My experience in the past is selling and using photographic equipment in a professional capacity. I wanted to buy a telescope. After doing a lot of research I found its really similar to buying a camera. My colleagues are in the process of buying a high end telescope for our clients to view the night sky here in Fuerteventura, but I would like one so I can learn at home in the meantime. Sure I can use the fancy one they will buy, but I’m occasional user, I have more of an amateur interest rather than a professional one.

Questions I used to always ask my customers in photography. ‘What is the main purpose for?’ ‘In what conditions?” ‘How often would you use it? ‘Is it for you? ” ‘what previous experience do you/or other person have?”  “What do you really want to do with a it?” ‘how much money do you want to spend?”

I’ve done a lot of research. What I used to find often with cameras is people have too much money, buy the latest thing that has all the bells and whistles and never use it to its full capacity and it sits in the corner of the room gathering dust and just looking pretty. It appears its the same with telescopes. I also asked an ex colleague who worked for a company who specialized in astronomy gear and he said the same. He said. “ If someone wanted to spend under £200 I would probably recommend a good pair of binoculars that last a lifetime. Often what happens is the  kind of telescope people think they want and what they really need are two different things.”

I was told do not even consider a telescope that advertises it power on the box (300x, 500x,650x, 725x).  Avoid telescopes that are advertised by their magnification — especially implausibly high powers like 600×. For most purposes, a telescope's maximum useful magnification is 50 times its aperture in inches (or twice its aperture in millimeters).  Even the best telescopes are limited to about 50x-75x per inch (25.4mm) of aperture. The big number with a ‘x’ after it, I was told  is actually a  marketing ploy and high-powered scopes tend to have fixed eyepieces. What you want is a removable eyepiece. Also even though these type of telescopes appear attractive advertised with a high number, all this means is the high magnification the light is gathered and spread over a larger area making it fuzzy and faint.  You should look for the magnification in the eyepiece. You calculate a telescope's maximum useful magnification by multiplying the size of the lens or mirror in inches by 50.  I was also told that alower power/magnification in the telescope tends to provide a better viewing experience.

Start with binoculars. If you don’t have much money and don’t want to spend over the £200 mark you may be happier with a very good pair of binos. Even for travel its actually quite a good idea to have a back up anyways of about 10x50, 7x50 for a more general use or an 8x56 or a 9x63 for something a bit more ‘astro’ and its less heavier, but can be slightly expensive. Buy something you can use, not something you will get frustrated with . If it rattles when you shake it, try a different pair of binos. Good telescopes will be expensive regardless of the type. Cheap binoculars are much, much more useful than cheap telescopes and  good binoculars can last you forever.

What you can see with a pair of binoculars look at this link: http://www.lightandmatter.com/binosky/binosky.html

binocular basics: http://www.chuckhawks.com/binocular_basics.htm

Should I get a refractor or a reflector telescope?

Now I had to get some help to explain this from another website as I couldn’t think of the any other way to explain it but share someone else’s informationhttp://www.astronomyforbeginners.com/equipment/telescope.php:

Reflector

Reflectors have one open end and a curved mirror at the back. Light is reflected and focused by this mirror onto a secondary mirror, which reflects it up into the eyepiece. Refractors are generally cheaper per inch of aperture and are in general better for the beginner on a budget, but aren't very good for ground observing, as the image is upside-down.

Refractor

refractor1.jpg

A refractor has a lens at the front which refracts light from the stars and focuses it at the eyepiece (often by means of a 45° mirror-in which case the image is reversed left-to-right). The image is the right way up meaning that these are better suited if you want to do ground observing as well. If the optics are good, then refractors can form better images, but are usually more expensive per inch of aperture.

Reflector telescopes have one optical surface (less mirrors) and tend to be cheaper and have no chormatic abberration. The mirror in this type of telescope may need recoating after years of use but if you are a beginner like me and will not use it outside on a rough surface (and tend to use it on your balcony like me) and not have much money then these type are a quick fix to look at the sky.

Refracting telescopes the light bends from one medium to another. A refractor uses two lenses. At one end, is the larger lens is called the objective. On the other end is the lens you look through, called the ocular or eyepiece. Also an advantage of a refractor is that by default they have a totally clear aperture and are low maintenance. A disadvantage is that some telescope lens/glass pieces will give off  chormatic aberrations. The only way I can describe it with my experience is light fringing around a subject like you get where you take a photo with a cheap lens on a sunny day sometimes the object has a faint fuzz around it, also kind of like a lens flare.  Inexpensive refractors have problems with false color, but they are often more compact and therefore better for traveling. Also, refractors tend to give more pleasing views when used in the daylight. Most reflectors tend to be very large by comparison, but will have better light gathering capability.  I was also told that whether buying either telescope look out for2.4 inch (60mm) and 3.1 inch(80mm) refractors and 4.5 inch and 6 inch reflectors are popular for most amateurs. Your new scope should have at least 1 eyepiece, and often 2 or 3. An eyepiece is rated by millimeters (mm), with smaller numbers indicating higher magnification. A 25mm eyepiece is common and appropriate for most beginners.While a higher magnification eyepiece may provide more details, it may be harder to keep an object in view, unless you are using a motorized mount. They also require the scope to gather more light to provide a clearer image.

A lower power eyepiece makes it easier to find objects and keep them in view. Lower magnification eyepieces require less light, so viewing dimmer objects is easier.

Remember the view through a telescope with not be exact to what you see in astrophotography on the internet or magazines. Planets will be tinier and some not in fantastic colours .

I started getting lost looking at all the brands. It seemed for over the £200 mark, the Meade does a introductory good telescope for anything over the £350 you are looking at more advanced Meade, Newtonians, Dobinsonians and Stellarvuemodels.  Lower cost options can include Maksutov-Cassegrains and “long” achromatic refractors.  Schmidt-Cassegrain Telescopes (SCT) can also offer pleasing views of the planets.

I recommend trying before buying. Observe through as many telescopes as you can, and ask as many questions as you can think of. Ask about setup time, maintenance and accessories.

This is a great list of things to help you set up your basic kit: http://www.astronomy.com/Equipment/How-To.aspx

To me it really is buying an extension of my camera equipment. Learning about glass wear, apertures and brands from various websites, magazines and asking professionals has helped me. Hopefully it won't just sit in the corner of my room.

Disclaimer: I am not a professional but someone who is interested. Within our team we have a professional astronomer but I write this article out of pure interest and passion for a subject am learning about.