An instrument used to measure the luminance (brightness) of a distant object. The object is viewed through a small telescope, and a mirror in the focal plane reflects an internal illuminated surface to the eye alongside the image of the object being...

Minimum object distance, often abbreviated as MOD, refers to the closest distance at which a camera lens or optical system...

The principles and techniques involved in the use of telephotometers to measure atmospheric extinction.

With relation to the equivalent beam candlepower of a searchlight, the candlepower of a bare source that would produce the...

An image-forming system having curved mirrors in place of transparent glass components. Mirror lenses are commonly used for...

The fiber optic connector standard for Nippon Telephone & Telegraph (NTT) installations, developed with Nippon Electric...

A telephoto lens form noted for its lack of distortion.

A compound lens so constructed that its overall length is equal to or less than its effective focal length.

Quantum entanglement is a phenomenon in quantum mechanics where two or more particles become correlated to such an extent...

Virtual histology refers to the use of digital technology and computational methods to simulate or recreate histological...

A device used to transmit and receive images that have been converted to electrical signals over regular telephone lines; it...

Laser-powered telephone device for analog communications that employs a vibrating plastic membrane as a transmitter to...

The generic term describing the class of light particles having no strong interactions.

That portion of the telecommunications network that runs from a local central telephone to the subscriber premises.

In a telephoto lens, the ratio of the overall length to the focal length of the lens. It is generally about 0.8 to 0.9 in...

1. A method of photographing distant objects with a lens of long focal length. 2. The reproduction of photographs over a...

Technology that relies on a highly efficient photodetector that can detect incoming light signals at one frequency and...

The focal length of a lens is the distance between the lens's optical center (or principal point) and the image sensor or...

The ratio between the focal length of a lens having a longer focal length than that of the standard lens used with a camera,...

The use of head-mounted displays and body-operated remote actuators to control distant machinery. Provides a virtual...

A factor that, when multiplied by the average candlepower emitted by a light source in a specified angular zone, reveals the...

The luminous intensity of a source of light expressed in candelas.

Also known as reversed telephoto lens. A lens consisting of an ordinary objective with a negative component near its front...

A wide-angle lens is a type of camera lens that has a shorter focal length than a standard or normal lens, allowing it to...