<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">apertures</topic></authority><related type="other"><topic>f-stops</topic></related><related type="broader"><topic>camera components</topic></related><variant type="other"><topic>aperture</topic></variant> <note xml:lang="en"><![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.' ]]></note></mads>