I have a pair of 16 x 50 binoculars, but I would like more zoom. I can't really make out aircraft or airlines above my house at 30,000ft + unless it's a really clear day.
I thought of using a telescope when the aircraft that high. That way, I would get much more magnification, but it'd be really hard trying to keep it in focus.
If I wanted a pair of binoculars that are more powerful than the ones I have now, I'd have to pay £250+ ($500 approx) and I'd rather not spend that much