DARK SKIES: Buy a telescope this Christmas
BUYING a telescope for stargazing is fraught with dangers to the uninitiated as to what is best for either a budding astronomer or for an adult to view the Moon, planets, nebulas, star clusters and galaxies.
While many photos of telescopes and their mounting system on the internet look classy, are you really sure they will do what you expect them to do?
Do you know the difference and the pros and cons of a reflector or refractor telescope?
For instance, when you see an ad for a $50-$150 telescope complete with a stand, be very careful.
It may look nice but when you set it up and look through it, the thing shakes like jelly at the slightest touch, it's hard to focus and whatever image it does give is utter rubbish.
This has been the norm in the past 45 years of poorly made cameras, lenses, telescopes and binoculars, first coming out of Russia and other Eastern Bloc communist countries.
Now it's China's turn and while we all love a bargain, there is no such thing as 'a good, cheap whatever' as in many cases it turns out a big disappointment.
Search the web, read the reviews and then make a decision.
Reflectors have a large, concave, aluminised reflecting mirror at the end of a white tube that reflects the light it collects back up to a small, flat elliptical mirror tilted at 45 degrees to the main mirror.
From here, the cone of light passes out at 90 degrees into a focuser, where you can insert an eyepiece that will magnify the image into a larger one, which is what the eye sees.
A reflector telescope's main mirrors range from 10cm to 30m, with the 20cm being the most universally used and enjoyed around the world. Like a window in the house, the larger it is, the more light it lets in, and it's the same with reflecting telescopes.
Reflectors are an ideal all-rounder telescope to glimpse faint objects like nebulas and galaxies, and view the Moon and planets when they present themselves. The smallest, practical reflector mirror telescope is 15cm.
Refractors, on the other hand, have an achromatic lens at one end of the tube and an eyepiece array at the other. Simply put, you are looking up the tube, not to the side as in the reflector.
Refractor telescopes are more robust and easier to maintain than a reflector and they range in size from 5cm to 120cm in diameter.
Refractors give the best views of the Moon and planets as there is no light being reflected off internal fittings, as in reflectors.
Refractors, due to their small aperture size, are not ideal to view nebulas and galaxies, as reflectors are.
The smallest, practical refractor telescope is 10cm.
So go online, read up both types with their pros and cons that fit in your budget, and if necessary let me give you an unbiased opinion of that product and brand name.
Wishing you all a happy, enjoyable Christmas.
If you want to book a night of stargazing at the observatory, send an email to firstname.lastname@example.org, phone 4164 6194 or book online at www.kingaroyobservatory.com.