What kind of camera lens would I need to take clear, detailed photos of a person from approx. 200 yards away?

A long one. At least 1000mm and it would have to be a good one.What kind of camera lens would I need to take clear, detailed photos of a person from approx. 200 yards away?
A 6ft tall person would subtend an angle of around .57 degrees from 200 yards away.





Using this data, on a 35mm camera, you would need about a 1200mm lens in order for the person's head to come to the middle of the frame if the frame were oriented as a horizontal shot.





In order for the person's head to come to the top of the frame with the image oriented vertically, you need about a 3500mm.





Divide these numbers by your crop factor to find out what would be needed on a less than full frame digital.What kind of camera lens would I need to take clear, detailed photos of a person from approx. 200 yards away?
i hear ya.. what ya need is a telescope with a camera mount.. get it
I would just get a hi megapixel camera and a 400mm lense and take a picture then you can crop on the computer later.








I would probably use a 50d and a 400mm f/5.6 lense. Both made by canon