Not sure if anyone has brought this up yet, but shooting from a airplane with a long lens is a very specialized skill set. I personally never go beyond 50mm (35mm format), as the sharpness degrades rapidly from that point on. Often I cannot get a decent image with anything more powerful than 35mm, which is a wide as many point-n-shoot cameras go.
Perfect air conditions where you can trim the airplane with slight head movements are an exception, but how often do you get those conditions? I remember times I could have probably gotten decent images from the airplane with a 300mm lens...and the reason I remember those times is because they were so rare.
Internal camera stabilization systems help a little, but the margins are still very tight. Also, unless you're willing to spend a couple grand for the camera body with advanced stabilization, internal stabilization is somewhat useless for airplane use.
Short of a external gyro-stabilizer ($900~$2800 for reconditioned units...plus you have to figure out how to power them), "long" shots from a airplane are completely impractical almost all of the time.
Folks wanting to take pictures from the airplane would do well to concentrate on good quality wide-angle options and leave any telephoto tinkering for the ground...preferably with a good tripod.




















