{HEAD ~ System} 300 is {TAIL ~ a second two stage imaging system} that compensates for the curvature of field aberration 
is
{ HEAD ~ System } 300 is { TAIL ~ a second two stage imaging system } that compensates for the curvature of field aberration
HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH