tS_1   1[mm]         Lens group 1 support thickness
tS_2   1[mm]         Lens group 1 support thickness
tS_3   1[mm]         Lens group 1 support thickness
dS_1   d0_1+2*tS_1   Barrel 1 inside diameter
dS_2   d0_4+2*tS_2   Barrel 2 inside diameter
dS_3   d0_6+2*tS_3   Barrel 3 inside diameter