<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31348779</termId><termName>apertures</termName><termType>PT</termType><termNote><![CDATA[ The opening that allows light to pass through an optical instrument, whether the image is to be fixed chemically on photographic materials or merely viewed as in a camera obscura. Apertures may be simple fixed holes, or of variable width or diameter achieved by mechanical means. To refer to aperture size settings, use 'f-stops.' ]]></termNote><termCreatedDate>2026-03-30 20:34:07</termCreatedDate><relation><relationType>UF</relationType><termId>31348780</termId><termName>aperture</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31322938</termId><termName>camera components</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31348775</termId><termName>f-stops</termName><termType>PT</termType></relation></term>  </Zthes>