Hello Adrian,
to IIS
Binos are a fantastic introduction to the night sky. Binos are the most underestimated visual instrument that there is. I have some 8 scopes, from 2" up to 17.5". But when ever I go bush my binos always come with me, regardless of what scope I take. Even from home, if I am chasing something just below naked eye, like a comet, my binos are the first item I grab.
Binos also show something a big scope cannot - context. But that I mean what surrounds a particular object in the sky, its immediate neighbourhood, all because its field of view will be larger than most scopes. Yes, while a big scope can show a lovely image of just the open cluster M7, what it cannot show you is the intricate lacework of dark nebulosity that surrounds its, set upon the mottled background glow of the Milky Way, nor the soft glow of the Milky Way surrounding the giant globular cluster Omega Centauri and the soft variations in that glow.
And because you are using both eyes, not one, our brain is so powerful that it combines the image from both eyes into one, giving a net image that is brighter and deeper than when using just one eye!
AND, binos can even show objects in the night sky that larger aperture scopes struggle to show, or even remain invisible to them! All because of the image being of low magnification, the available light of an object is condensed into a small patch, and the object can be much easier to see!
Think you can't see galaxies with binos? Think again! No, of course you won't see the spiral arms of most of them, and for that matter most scopes cannot until you start pushing the aperture to 10" and over, but there are dozens that are easily within the grasp of a set of 7X50mm binos. Even more with a set of 11X70. Still doubt this? The Sombrero, the Southern Pinwheel, Centaurus A, all of these are easy pickings with just a 30mm finder scope, and visible in 7X50 binos from all but the most light polluted skies - I can see them from my home in Sydney.
The thing you should consider about binos if you don't have a set already is finding a pair that will be good for both astro and terrestrial viewing. The first number in a bino description, such as 7X50 and 11X70, is the magnification, the second is the size of the front lens in millimeters. You would want to keep the size of the binos no larger than 70mm if you are going to use them for terrestrial viewing otherwise they start getting much too heavy. Magnification, below 15X or your hands will shake way too much to be usable (much of the shaking is actually due to your pulse). If you are considering a set of binos just for astro, then you will need to also look for a suitable tripod or other mount to put them on. But even with 7X50 binos, extended period of hand holding them at night can be tiresome and shaky, so you can either also set them on a tripod, or rest them on a post, your car, anything really, and this will make things much easier.
If this is you first foray into astro, binos make for a brilliant introduction. If the astro bug bites hard after you start using binos, great! and the binos will still remain relevant and a useful tool. If the astro bug doesn't bite, then the binos still won't go to waste as they are always a handy terrestrial tool. Win win really
My very first optical bit of astro gear was a set of modest opera glasses. Small, low magnification, but they were certainly capable of showing me dimmer things than I could see naked eye
I still have them too, though my kids use them today, and I am glad they look after them too. But like I said at the very start, my binos go with me everywhere. If forget some bit of gear needed for the scope I planned to use and turns out I can't use it, the binos mean the session is not a bust
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Yep, binos are a good intro to astro
Alex.