Table 7. Solutions computed from PP Matrices derived from Table 6 reveal the geometry of the biplanar imaging. Here we are able to compute the point source in AP and LAT. In addition, K-matrix (intrinsic matrix) components are shown including principal point, skew angle (theta), and a simple average between alpha and beta. The planes are computed using the focal distance obtained from a quadratic solution and the normal of the detector plane. The normal of the computed detector plane relative to the normal of the normalized plane is also shown as the "AP/LAT Normal to Normal Angle.".

AP = Antero-Posterior; LAT = Lateral; VERT = Vertical; PP = Perspective Projection; Combined = Simple average of Alpha and Beta for focal length calculation; Alpha = Alpha length from intrinsic matrix for focal length calculation; Beta = Beta length from intrinsic matrix for focal length calculation; 

Theta = Angle used to determine skew angle (here presented in radians);

Distance from Point Source to Plane = Focal Length, which was calculated using Quadratic Solution;

AP/LAT Normal-to-normal Angle (degrees) = normal of computed detector plane relative to the associated normal of a normalized plane.

Solutions in AP and LAT Computed from PP
AP Point Source (AP, LAT, VERT):
655.7883	-6.05706	93.15404
Combined	Alpha	Beta	Uo	Vo	Theta
1173.785	1177.416	1170.154	146.9495	16.4229	1.581723
AP Plane Calculation using Intrinsic Matrix from PP (AP, LAT, VERT):
-511.98	0	0
-513.434	0	100
-516.476	-100	0
Focal Distance AP (Quadratic Solution):
1168.091
AP Normal-to-Normal Angle (degrees): 2.70572703691867
LAT Point Source (AP, LAT, VERT):
-4.4651	-657.583	5.275153
Combined	Alpha	Beta	Uo	Vo	Theta
1171.379	1169.453	1173.304	209.5675	101.2284	1.571102
LAT Plane Calculation using Intrinsic Matrix from PP Reverse Cross Product (AP, LAT, VERT):
0	515.5404	0
0	510.9394	100
-100	516.9381	0
Focal Distance LAT (Quadratic Solution):
1171.589
LAT Normal-to-Normal Angle (degrees): 2.75303244159637