![]() Some finders are very fiddly to adjust, and this is the biggest weakness of many telescopes, but at least by day you can see what’s going on and the object is not not going to move as the Earth turns, unlike objects in the sky. Keep this in the field of view of the main telescope and adjust the finder to show exactly the same point. Choose something quite distant and easily recognised – the end of a television aerial or antenna is a favourite. The crucial thing is to find something through the main telescope first, not the other way round, and it’s far easier to do this by day as you have a much bigger choice and can usually find something much more easily. It could be either a small, low-power telescope, or increasingly these days because they are cheaper, a red-dot finder. The next favourite mistake is not knowing how to align the finder telescope, the small device on the side that is there to help you find objects. So the crucial thing when trying to find any object, is to start by using a low magnification, which means using the eyepiece with the largest number on it, generally 20 or 25 mm. Even finding a big object like the Moon can be tricky using a high magnification. ![]() And even worse, you see less of the sky, just like using the zoom when taking a photo. Obviously, things look bigger, but this means that the amount of light in the object is spread over a bigger area, so things actually look dimmer. Three things happen when you increase the magnification. Low magnifications are as useful when looking through a telescope as high ones, both for beginners and advanced observers. A 10 mm eyepiece gives a higher magnification than a 25 mm eyepiece, even though it has a smaller number and usually is smaller as well. Two is a bigger number than one, right? So how come a second magnitude star is fainter than a first magnitude star? That’s another story, but it’s true of eyepieces as well. ![]() Astronomy is full of numbers, and some of them seem to go the wrong way. Perhaps I should stop right now and let someone else take over, but there’s no-one else around so you’re stuck with me.įirst up, and favourite mistake by a long way, is starting with too high a magnification, which comes down to not knowing your eyepieces. So obviously my powers of explanation aren’t very good. And every time, wouldn’t you know it, people call me over to help them because they can’t see anything through their telescope, and always it’s something simple. Then, weather permitting, we go out and start observing. Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by the Salt Lake Astronomical Society.Ī couple of times each year I take part in weekend courses for beginners in astronomy, and every time we go through the basics of setting of a telescope and starting to observe. He is Vice President of the Society for Popular Astronomy, and Chairman of the West of London Astronomical Society. This show looks at the most likely things to go wrong, and helps you start seeing stars.īio: Robin Scagell is a British author and broadcaster on astronomy, and runs Galaxy Picture Library. But then – what’s gone wrong? Instead of sparkling stars, you see absolutely nothing! This isn’t uncommon, even with the very latest all-singing, all-dancing automatic telescopes. Link: Description: You’ve just bought your very first telescope, and you’re excited by all the wonders you’re going to see and the things you’re going to discover.
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