The base is preferably formed such that the registration surface 22 is in {HEAD ~ a precise location} with {TAIL ~ respect} to the optical system so that the active surface 16 of the substrate is at a focal point within a few microns 
with
The base is preferably formed such that the registration surface 22 is in { HEAD ~ a precise location } with { TAIL ~ respect } to the optical system so that the active surface 16 of the substrate is at a focal point within a few microns
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH