No Paul, It serves the same purpose as a finder scope except its not a mini telescope like a finderscope. All it is is a little lense inside the casing that shines a red bullseye target up onto a piece of perspex like a HUD (Heads up display on a fighter jet). You look along the length of your scope through this little piece of perspex with the red bullseye supperimposed on your view like a HUD. Nothing is magnified, its just like looking along your scope through a tiny little window with a bulleyes. You move your scope untill you get the object you want to look at in centre of the bullseye. Seeing as you would have the telrad aligned with your scope like you would with a normal finderscope, whatever is in the centre of the bullseye should now be visible in the actual telescopes eyepiece.
A normal telescopic finderscope say a 9x50 will magnify a view by 9 times and thus the field of view in the finderscope will be like those in a pair of 8x50 bino's for instance, ie. a small patch of sky. So with a normal finder scope you still have to roughly align your telescope on the object which will hopefully then be in the field of view in the finderscope, and then you would centre the object under the cross hairs to be able to see it in your actual telescope eyepeice. A telrad cuts out all that. Centre something in the bullseye and go straight to your eyepiece. There are actually 2 bigger circles around the bullseye too. Many books and magazines have their star charts calibrated to the telrads bullseye and rings too and show where to position the bullseye/rings in relation to stars so that the object in question is in centred in the eyepiece.
Like this
www.jsaonline.com/charts/charts/m036.htm
So in this example you would look through the telrad window with the super-imposed bullseye and position the rings with that star down the bottom right. M36 should now be in the EP. You also can see where NGC 1907 is in relation to your bullseye. You would then know where to vove the centre of the bullseye to get NGC1907 in the eyepiece.
....and to tie this back in with the thread topic. The little perspex window that you look through dews up very quickly. The lads are talking about little heaters that warm up the little window/HUD of the telrad to clear dew/stop it forming.
