Further, {HEAD ~ the five lens system} can be implemented as {TAIL ~ part} of a fixed focus imaging system, or in conjunction with a variable focus optical magnification imaging system 
implemented as
Further , { HEAD ~ the five lens system } can be implemented as { TAIL ~ part } of a fixed focus imaging system , or in conjunction with a variable focus optical magnification imaging system
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH