Hence, the eyepiece 3 which is connected integrally with the dioptry adjusting pin 8 is positioned at {HEAD ~ a constant photographing position}, permitting {TAIL ~ a photographing operation} 
permitting
Hence , the eyepiece 3 which is connected integrally with the dioptry adjusting pin 8 is positioned at { HEAD ~ a constant photographing position } , permitting { TAIL ~ a photographing operation }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL