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Message: <blockquote data-quote="mak" data-source="post: 1732821" data-attributes="member: 774">Fireform.In what way are Leica and Zeiss being left behind optically.Transmission?Stray light?OR DO YOU MEANDistortion, as in:In eyepieces among other aberrations distortion occurs. One must distinguish between rectilinear distortion and angular magnification distortion.To correct rectilinear distortion = straight lines appear straight in the centre and at the edge of the field of view the magnification over the field has to follow the equation:magnification = tan w'/tan w (w' = image angle with telescope, w = image angle w/o telescope)In doing so the image appears to be bent ("image bending") because while moving the telescope over the object area the foregound is "rolling" in front of the background (infinity).To correct angular magnification distortion = the distance between two lines is the same in the centre and at the edge of the field of view the magnification over the field has to follow the equation:magnification = w'/w (w' = image angle with telescope, w = image angle w/o telescope)In doing so straight lines appear curved in a pin cushion fashion with the curvature becoming greater with increasing distance from the centre of the field of view. As you see from the equations it is impossible to correct rectilinear distortion and angular magnification distortion at the same time. Optic designers therefore "mix" the two equations (in my humble words) and correct both only partly to form a compromise. How the compromise looks like is "a matter of taste" of the optics designer.mak.</blockquote>

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