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Message: <blockquote data-quote="Eyelight" data-source="post: 420993" data-attributes="member: 24753">I should have guessed.  I had it as a A340 and calculated the height at 34,248.78 feet based on the image size.At that distance, you could set your focus manually and not use AF.  Reason is using f/7.1 at 240mm focal length the hyperfocal distance is 1,326.53 feet; meaning everything from 1326.53/2 (half the hyperfocal distance) to infinity would be in an acceptably sharp focus.You can do this on a lens with a distance markings and DOF scale by setting the infinity mark just inside the aperture value you are using. If the lens does not have a DOF scale, you can use a DOF calculator to find the hyperfocal distance, and then focus on an object that is at a greater distance.</blockquote>