I remember when I started my love affair with the telescope, a good few years ago now. On my very first observing session I thought I could get by without attaching a finderscope to the telescope at all.
Ridiculously, I thought I’d simply be able to point the scope in the general direction and then use the eyepiece to hone in. Needless to say that by my second observing session I had the finderscope installed before I did anything else.
Like telescopes, finderscopes come in all different shapes and sizes, in effect they are mini telescopes that ride piggyback on your main scope. They show you a low magnification view of the sky with a number of times more light grasp than the human eye.
The Sky-watcher 9×50 finder sits proudly atop my 12″ Dobsonian. It’s around 9 inches in length and around 3 inches at it’s fattest point. It provides 9 times magnification, just enough to show prominent globular clusters as slightly elongated fuzz patches and has 50 times the light grasp of the naked eye.
When you look through the finder you will see two thin black lines meeting in a cross slap bang in the middle. It’s best to find a bright star or perhaps a planet if there’s one high in the sky and center it in a low power eyepiece. You then adjust the screws so the star/planet is as centred in the finder as you can get it. Then switch to a higher magnification EP and repeat. The higher the magnification used the more precisely aligned the finderscope will be.
The finderscope is an invaluable tool and as such you should always try and get the best one you can afford. The skywatcher 9×50 is a great choice and comes in at just shy of £50 (including the bracket). Its 50 times light grasp enables me to see stars down to about magnitude 8 on a good night which is great considering my naked eye limit is about 4.5.
The better your finderscope is the less time you spend searching and the more time you spend observing. The Sky-watcher 9×50 is amongst the best finderscopes I’ve used and as such comes highly recommended, not only is it a steal at £50 but you also get your choice of colour for the vain astronomers amongst us 8^) Metallic blue, black and white like my one.