wherein an incidence angle of {TAIL ~ the image beam} to {HEAD ~ the optical lens} is between 0 degrees and 90 degrees 
wherein an incidence angle of { TAIL ~ the image beam } to { HEAD ~ the optical lens } is between 0 degrees and 90 degrees
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH