I was told that a scope that has NO external adjustment for "windage" or lateral alignment with the bore, (compared to a windage adjustable base,) can only have its crosshairs reticle adjusted accurately for one distance, and will be off to one side or the other at closer or farther distances.
This is an exacting precision question, and whether or not the difference is negligable or noticable is not the point. The point of the question is as to how a scope is made and the technical aspect of alignment.
Some scope mounts, especially the rail type, allow NO alignment adjustments of the scope externally, to correct any optical or mechanical misalignment LATERALLY.
Theoretically and actually, assume for the moment that the scope is collimated correctly, and mounted directly over the bore, its optical system plumb and windage adjusted in perfect vertical plane alignment. The reticle should be able to be adjusted for perfect zero windage at ALL distances.
BUT if (and assume so ) the scope base and rings assembly has to be just a bit off perfect external alignment, assume an amount that would require internal crosshair correction, actually decentering the cross-hairs from the scopes true optical axis, is this then going to make the POA laterally dependant on one set distance, ? OR is the new corrected internal alignment theoretically and/or actually corrected for all distances LATERALLY in spite of the de-centering of its cross-hairs from the scopes true optical axis. ?
Please note that the vertical parallax error is not in question, and that there is no question that the usual adjustments for range would apply in the up and down dimension.
The upshot of the problem, is the question of whether a scope base with lateral adjustment would be needed to maintain a true zero'd windage adjustment reference.
IF the question is understood, answers would be welcomed.
This is an exacting precision question, and whether or not the difference is negligable or noticable is not the point. The point of the question is as to how a scope is made and the technical aspect of alignment.
Some scope mounts, especially the rail type, allow NO alignment adjustments of the scope externally, to correct any optical or mechanical misalignment LATERALLY.
Theoretically and actually, assume for the moment that the scope is collimated correctly, and mounted directly over the bore, its optical system plumb and windage adjusted in perfect vertical plane alignment. The reticle should be able to be adjusted for perfect zero windage at ALL distances.
BUT if (and assume so ) the scope base and rings assembly has to be just a bit off perfect external alignment, assume an amount that would require internal crosshair correction, actually decentering the cross-hairs from the scopes true optical axis, is this then going to make the POA laterally dependant on one set distance, ? OR is the new corrected internal alignment theoretically and/or actually corrected for all distances LATERALLY in spite of the de-centering of its cross-hairs from the scopes true optical axis. ?
Please note that the vertical parallax error is not in question, and that there is no question that the usual adjustments for range would apply in the up and down dimension.
The upshot of the problem, is the question of whether a scope base with lateral adjustment would be needed to maintain a true zero'd windage adjustment reference.
IF the question is understood, answers would be welcomed.