With too small a pinhole, however, the sharpness worsens, due to diffraction.

To protect their eyes the aliens wear opaque sclera contact lenses with small pinholes for vision.

With good optics and a very small pinhole, one could even approximate a plane wave.

To use a very small pinhole, one must use a focusing lens with a low f-number, and ideally the lens should not add significant aberrations to the beam.

In paper-insulated high-voltage cables, partial discharges begin as small pinholes penetrating the paper windings that are adjacent to the electrical conductor or outer sheath.

The outline is punched with small pinholes using a sewing tracing wheel.

A small black pinhole had appeared in the center of each lesion on his face.

Viewing can be safely done in projection by letting the sunlight pass through a small pinhole onto a flat surface a foot or two away.

The reference beam is generated by diffraction from a small pinhole, about half the diameter of the Airy disk, in a semitransparent plate.

The surface of the table has a series of small pinholes drilled in it.