Aperture lamps include reflectors over the non-aperture area. In addition to the primary aperture, many foraminifera have "supplemental" apertures. This is used in conjunction with a higher numerical aperture lens. The sine of this maximum angle is the numerical aperture (NA) of the fiber. Like objective lenses, condensers vary in their numerical aperture (NA). The length is measured from the end of the aperture to the apex. Camera film is supplied ready mounted in aperture cards. The apparatus consisted of a dark chamber with a small aperture that let light in. Target aperture sights are designed for maximum precision. It is inserted into the instrument near its aperture. It is the reciprocal of the relative aperture. The shape of the aperture is elliptical. The height of the aperture is . One then speaks of a telescope as having, for example, a 100-centimeter "aperture". Typically this means somewhere in the middle of the aperture range.