Gain

Gain, also called brightness gain or luminance gain, is the measurement of the increase in brightness between the input and the output of an image intensifier tube.

Specification

There are two different units used to specify gain, imperial and metric.

Imperial

Gain specified in imperial units uses the units of foot-Lamberts by foot-candle (Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\textstyle \mathrm{fL} / \mathrm{fc}} ).

Measurement

To measure gain in accordance to the MX-10160/AVS-6 specification, the photocathode is exposed to Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\textstyle 2 * 10^{-6} \mathrm{fc}} of input light. A photometer is then used to measure the luminance (brightness) of the phosphor screen (in Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\textstyle \mathrm{fL}} ). The resulting value is divided by Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\textstyle 2 * 10^{-6}} to obtain the gain in Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\textstyle \mathrm{fL} / \mathrm{fc}} .

To further test auto brightness control, the same procedure is usually repeated with Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\textstyle 2 * 10^{-4} \mathrm{fc}} .

Manufacturers

The following manufacturers are known to use imperial units when specifying gain:

• Elbit Systems of America
• L3Harris

Metric

Gain specified in metric units uses the units of candela per square-meter per lux (Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\textstyle \mathrm{cd} / \mathrm{m}^2 / \mathrm{lx}} ).

Manufacturers

The following manufacturers are known to use metric units when specifying gain:

• Photonis Technologies SAS

Conversion

To convert between metric and imperial units, use the following formula:Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \mathrm{G}_{\mathrm{fL} / \mathrm{fc}} = \mathrm{G}_{\mathrm{cd} / \mathrm{m}^2 / \mathrm{lx}} * \pi}

So, a gain of 10,000 Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\textstyle \mathrm{cd} / \mathrm{m}^2 / \mathrm{lx}} is equivalent to roughly 31,416 Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\textstyle \mathrm{fL} / \mathrm{fc}} .