Yes, I have, actually. I used to use a telescope at about 25-30X to watch the faces of pilots as they approached the runway just for shits and grins. The expressions on the pilots faces can be hilarious! When the plane is coming towards you- or away- all you have to do is keep turning the focus as it approaches or recedes from you to keep the plane in focus. You're correct if the plane is travelling sideways to you, then it is almost impossible to capture an image of the plane with a video or digital camera, unless you're using a shutter speed of 1/1000 of second and even then you gotta be good! Whatever magnification you're using will also speed up the apparent motion of an object by the same factor as the magnification- which is why an image of an astronomical object will appear to travel faster through the field of view than it will to the naked eye. But that rule of thumb only applies if the object is travelling more or less sideways to you. It doesn't work that way if it's coming towards or away from you. Watch the road in front of you through a pair of binoculars while you're riding in a car with a friend and you'll see what I mean. Then look through the binoculars out the side window. You'll definitely see the difference!

Gem

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There is no political solution to our troubled evolution.

"Reality, the left-wing liberal conspiracy. "
Credited to Angry American.