diameter-limit

См. также в других словарях:

• limit of perception — the minimum visual angle below which perception is impossible: an object to be perceived must subtend a visual angle of four or five minutes, thus making its image on the retina about the size of a retinal cone of 3.3–3.6 micrometers in… …   Medical dictionary

• Dawes' limit — diffraction pattern matching Dawes limit Dawes limit is a formula to express the maximum resolving power of a microscope or telescope. It is so named for its discoverer, W. R. Dawes, although it is also credited to Lord Rayleigh. The formula… …   Wikipedia

• 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

• Selection cutting — is the silvicultural practice of harvesting a proportion of the trees in a stand. Selection cutting is the practice of removing mature timber or thinning to improve the timber stand. This system may be used to manage even or uneven aged stands.… …   Wikipedia

• Biltmore stick — A Biltmore stick is a tool sometimes used to measure various tree dimensions, such as diameter at breast height and height. It looks much like an everyday yardstick. A Biltmore stick is considered to be only marginally accurate. Some foresters… …   Wikipedia

• environment — environmental, adj. environmentally, adv. /en vuy reuhn meuhnt, vuy euhrn /, n. 1. the aggregate of surrounding things, conditions, or influences; surroundings; milieu. 2. Ecol. the air, water, minerals, organisms, and all other external factors… …   Universalium

• 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

• Optical telescope — Eight Inch refracting telescope (Chabot Space and Science Center) An optical telescope is a telescope which is used to gather and focus light mainly from the visible part of the electromagnetic spectrum for directly viewing a magnified image for… …   Wikipedia

• Fly system — Fly loft of the Theater Bielefeld in Germany A fly system, flying system or theatrical rigging system, is a system of lines (e.g. ropes), blocks (pulleys), counterweights and related devices within a theatre that enable a stage crew to quickly,… …   Wikipedia

• Superlens — A superlens, super lens or perfect lens is a lens which uses metamaterials to go beyond the diffraction limit. The diffraction limit is an inherent limitation in conventional optical devices or lenses.[1] In 2000, a type of lens was proposed,… …   Wikipedia