| Aperture (Pinhole). To place the aperture, click anywhere in the simulation. The aperture has a height and depth equal to the height of the simulation window. The opening of the aperture is centered on the central axis (dashed line). The Aperture blocks all incident light except the light incident on the opening. An alternative view of this object is available. You can change the size of the hole by dragging on the hotspots located on either side of the opening. These are hard to see, so click right on the edge of the opening. In the aperture's Properties Box, you can set the opening to its smallest possible size by clicking the box labeled pinhole.