DV_REF
float dz = sqrt(1.0 - (DH_REF*DH_REF + DV_REF*DV_REF) * (0.5 + 0.5/Z_CUT_RATIO) * (0.5 + 0.5/Z_CUT_RATIO));
fGeometry.yz_max = (0.5*DV_REF)/fGeometry.z_max;
zoom = (float)dv*(fDepthRef/DV_REF);
dy = fCamera.Axis(1)*(DV_REF*0.5);