The resistance of individual grains of an abrasive to breaking down under pressure. If the grains break down under relatively low pressure, the abrasive is said to be more friable.

The formation of microimages for microreduction. The technique is used, for example, in the production of precision reticles...

An optical system in which the only image-forming elements are curved-surface mirrors; e.g., a Cassegrain lens system.

A two-mirror lens design used in astronomical telescopes, the primary being a parabola, the secondary a smaller hyperbola....

A Cassegrain telescope having a parabolic primary mirror, a spherical secondary mirror and a zero-power doublet in the...

Pixel binning, also known as pixel merging or pixel combining, is a technique used in digital imaging and camera technology....

A fluoroscope equipped with a magnified, fine-grained fluorescent screen to determine the fluorescence emitted by a...

The process whereby a rotating wheel carries grains of an abrasive, suspended in a vehicle, across the surface of the...

A telescope similar to the customary Cassegrain telescope, but having a primary mirror that is ellipsoidal and a secondary...

In a microscope, the diaphragm located between the Bertrand lens and the eyepiece, which is closed during conoscopic viewing...

In a multicrystalline material, the meeting point between crystallites.

In photolithography, an opaque material used in masks that has a lower optical density and grainier composition than chrome.

The growth of particular grain fragments in a metal or alloy, at the expense of others, that occurs when the metal or alloy...

A crude area on the polished surface, produced during coarse grinding, that subsequent fine grinding does not remove, owing,...

An emulsion in which grains of the photosensitive material silver halide are deposited. Each grain, when exposed to light,...

A crystal having the axes of its grains aligned so that they have directional magnetic characteristics.

A form of Cassegrain telescope having a concave hyperbolic primary and a convex hyperbolic secondary. This form permits the...