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