- December 2, 2020 - Planétarium : Experience
When you start out in astronomy, choosing a telescope is difficult because there’s a huge range of instruments, some of which may require a considerable investment. Here’s some advice that will help.
Patience is the key to success
Taking up a hobby like astronomy demands patience. Spending long evenings and nights scanning the starry sky means you have to take your time. Begin by admiring the sky with the naked eye, using a star wheel. That way you’ll learn to recognize the constellations and see if you enjoy observing the sky for an extended period.
Begin with binoculars
I suggest you next use binoculars, which are a good tool for getting familiar with the sky via a piece of equipment somewhere between our eyes and a telescope. Moreover, binoculars are useful for other things than astronomy.
For someone starting out I recommend 10X50 binoculars. The first number corresponds to the binoculars’ magnification power, and the second to the diameter of the lens in millimeters.
The diameter, more important than magnification
What’s important in astronomy is not the magnification but the diameter of the aperture on the apparatus. The instrument focuses light into a narrow beam that enters our pupil to form an image on the retina of our eye. The bigger its diameter, the more light will be captured by the instrument. The image will then be clearer, and we can use a higher magnification.
A word of caution is needed here: don’t trust the capabilities of the instrument given by the maker. Most manufacturers provide impressive information that isn’t applicable when you observe the sky at night. Remember that when you magnify with an optical instrument, the image is darker, because only part of the field-of-view is used.
In astronomy, the maximum magnification of a telescope is equivalent to two times the aperture of the apparatus in millimeters. The diameter is always provided on the packaging (sometimes in the form of D=xxx mm). Thus, an instrument with a 60mm aperture will give a magnification of roughly 120 X.
An entry-level instrument
In closing, there’s a telescope for beginners now made by the Celestron company (an excellent reference in astronomy): the FirstScope. This is a telescope with a 76mm aperture and a tabletop design, and is very easy to manipulate. The price is only $70. For someone starting out in astronomy, it’s unquestionably the best quality/price ratio.
If you want an instrument on a tripod, a 60mm refractor telescope is the ideal tool to start with. That type of instrument sells for about $150, so it’s still affordable. For those who are deeper into it, a 150mm or even 200mm telescope may meet your needs. But you’ll often have to spend more than $1,000 for a quality instrument. I suggest it only for those who are already experienced and who’ve developed a passion for astronomy.
It only remains for me to wish you wonderful observations and that you enjoy discovering the riches of the starry sky.
