High-level aircraft spotting

At present I use 8X30 and 10X50 binoculars for aircraft, but find that
high-flying A/C (contrail height) can be difficult to make out. I'm
wondering if a pair of large binoculars, say 15X70, would be better than a
spotting scope ( 12-36 X 50) or perhaps (18-55 X 65)?

Anyone have practical experience of any of these?

Regards

Pat Macguire

I'm guessing that the trouble with really high power stuff is field of
vision and the speed of transit of the object across that field.

You might be better the get high power lenses, on a tripod and add a
digital camera. Then you can enlarge the image and make out the
details.

I have done this (the digicam bit) FROM and aircraft both to the ground
and to other passing a/c and it's amazing how it helps.

HTH

david