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.

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

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

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

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

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

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

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

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

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

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

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

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

In a multicrystalline material, the meeting point between crystallites.

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

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

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