The values below are results of geometric calibration of the lens, from image 31 ; radius = 25 ; radp=(radius*3.1416 / 180) / 1.4 ; (1.4*sin(radp)/cos(radp)) ~0.45103263975955523764 ; radr=(radius*3.1416 / 180) ; (1.4*sin(radp)/cos(radp)) / radr ~1.03368825002189894036 is the magnification of the distance due to Nikon990 projection, short focus, for Pi3 Ori and Iota Per. ; 0.0465 * 1.033688 0.048066492 ; radius=15 ; radp=(radius*3.1416 / 180) / 1.4 ; radr=(radius*3.1416 / 180) ; (1.4*sin(radp)/cos(radp)) / radr ~1.01182171837937129469 ; 0.04735 * 1.0118 0.04790873 ; radius=11 ; radp=(radius*3.1416 / 180) / 1.4 ; radr=(radius*3.1416 / 180) ; (1.4*sin(radp)/cos(radp)) / radr ~1.00631603187931093248 ; 0.0477 * 1.006 0.0479862 ; 180*sqrt(7.45e-7)/3.14159 / 0.048 ~1.03029098133620647507 Is the coefficient the focal length should be multiplied by or CCD width divided by.