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