Vapor
11-26-2007, 09:57 PM
I am looking for a spotting scope under $600 capable of measuring the angular height of an object (ex. mil-dot). I'll be using it for detailed scanning and distance measurement of targets with known height/width.
I’ve only seen the Leupold Mark 4 spotting scope, but can’t afford it.
Does anyone know of any others? I’ve been searching for a few months and come up with nothing. I suppose I could get a rifle scope, but I much prefer the Porro prism design, and quick focus wheel of spotting scopes. the shorter focusing distance
I have a laser range finder, but it needs a completely clear line of sight. It is also limited to about 500 yards for non reflective objects.
For anyone who enjoys technical information here's more information on why a spotting scope design will generally have better optical qualities than a rifle scope. In rifle scopes the light entering the objective lens has a shorter focal length. Given the small diameter of the tube, relative to a spotting scope, the light must be focused at a shorter distance. This means the objective lens must have a smaller radius of curvature. all else being equil, a lens with larger radius of curvature will be more uniform in curvature and focus light and a more precise location (less spherical aberration). The longer light path (of spotting scopes) also allows for better absorption of stray light within the tube.
I’ve only seen the Leupold Mark 4 spotting scope, but can’t afford it.
Does anyone know of any others? I’ve been searching for a few months and come up with nothing. I suppose I could get a rifle scope, but I much prefer the Porro prism design, and quick focus wheel of spotting scopes. the shorter focusing distance
I have a laser range finder, but it needs a completely clear line of sight. It is also limited to about 500 yards for non reflective objects.
For anyone who enjoys technical information here's more information on why a spotting scope design will generally have better optical qualities than a rifle scope. In rifle scopes the light entering the objective lens has a shorter focal length. Given the small diameter of the tube, relative to a spotting scope, the light must be focused at a shorter distance. This means the objective lens must have a smaller radius of curvature. all else being equil, a lens with larger radius of curvature will be more uniform in curvature and focus light and a more precise location (less spherical aberration). The longer light path (of spotting scopes) also allows for better absorption of stray light within the tube.