The thin film filter is formed on {HEAD ~ each} of {TAIL ~ the first and second lens portions} 
of
The thin film filter is formed on { HEAD ~ each } of { TAIL ~ the first and second lens portions }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL