{TAIL ~ The beam splitter} 30 may split the image beam C into a first projecting beam C1 and {HEAD ~ a second projecting beam} C2 
{ TAIL ~ The beam splitter } 30 may split the image beam C into a first projecting beam C1 and { HEAD ~ a second projecting beam } C2
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH