The eyepiece can be brought to {HEAD ~ a photographing position} which is within {TAIL ~ the extent} of adjustment of the dioptry 
is within
The eyepiece can be brought to { HEAD ~ a photographing position } which is within { TAIL ~ the extent } of adjustment of the dioptry
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH