Valonkeräys

Valonkeräys, also known as photometry, is the science of measuring light, along with its spectral composition and photometric properties. It is a branch of optics that deals with the measurement of light intensity, color, and other properties. Photometry is used in various fields, including astronomy, photography, and lighting design.

The basic unit of measurement in photometry is the lumen, which is a measure of the total quantity of light emitted by a source. Other important units include the candela, which measures the luminous intensity of a light source in a specific direction, and the lux, which measures the illuminance, or amount of light falling on a surface.

Photometric measurements can be made using various instruments, such as photometers, spectrophotometers, and colorimeters. These instruments use different techniques to measure light, including the use of filters, gratings, and detectors.

Photometry is important in many applications, such as in the design of lighting systems, where it is used to ensure that the right amount of light is provided for a given space. In astronomy, photometry is used to measure the brightness of stars and other celestial objects. In photography, photometry is used to determine the correct exposure settings for a camera.

In summary, photometry is a crucial field of study that deals with the measurement of light and its properties. It has numerous applications in various fields, including astronomy, photography, and lighting design.