- focal diameter
- фокальный диаметр (напр. лазерного пучка)
Англо-русский словарь по машиностроению. Академик.ру. 2011.
Англо-русский словарь по машиностроению. Академик.ру. 2011.
focal ratio — noun the ratio of the focal length to the diameter of a (camera) lens system • Syn: ↑f number, ↑stop number, ↑speed • Hypernyms: ↑ratio * * * noun : f number … Useful english dictionary
Photoacoustic imaging in biomedicine — Photoacoustic imaging, as a hybrid biomedical imaging modality, is developed based on the photoacoustic effect. In photoacoustic imaging, non ionizing laser pulses are delivered into biological tissues (when radio frequency pulses are used, the… … Wikipedia
TV and FM DX — TV DX and FM DX is the active search for distant radio or television stations received during unusual atmospheric conditions. The term DX is an old telegraphic term meaning long distance. VHF/UHF television and radio signals are normally limited… … Wikipedia
f-number — focal distance divided by the effective diameter of the camera lens aperture (Photography) … English contemporary dictionary
Depth of field — The area within the depth of field appears sharp, while the areas in front of and beyond the depth of field appear blurry … Wikipedia
F-number — In optics, the f number (sometimes called focal ratio, f ratio, or relative aperture [Smith, Warren Modern Lens Design 2005 McGraw Hill] ) of an optical system expresses the diameter of the entrance pupil in terms of the focal length of the lens; … Wikipedia
telescope — /tel euh skohp /, n., adj., v., telescoped, telescoping. n. 1. an optical instrument for making distant objects appear larger and therefore nearer. One of the two principal forms (refracting telescope) consists essentially of an objective lens… … Universalium
Circle of confusion — For the closely related topic in microscopy, see Point spread function. In optics, a circle of confusion is an optical spot caused by a cone of light rays from a lens not coming to a perfect focus when imaging a point source. It is also known as… … Wikipedia
Hyperfocal distance — In optics and photography, hyperfocal distance is a distance beyond which all objects can be brought into an acceptable focus. There are two commonly used definitions of hyperfocal distance , leading to values that differ only slightly:The first… … Wikipedia
optics — /op tiks/, n. (used with a sing. v.) the branch of physical science that deals with the properties and phenomena of both visible and invisible light and with vision. [1605 15; < ML optica < Gk optiká, n. use of neut. pl. of OPTIKÓS; see OPTIC,… … Universalium
Telescopic sight — Scope redirects here. For other uses, see Scope (disambiguation). View through a 4x rifle scope. A telescopic sight, commonly called a scope, is a sighting device that is based on an optical refracting telescope. They are equipped with some form… … Wikipedia