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19-1104: FBD may refer to: Science and technology [ edit ] Flange back distance , in mounting camera lenses Free body diagram , helps visualise forces on bodies Fully Buffered DIMM , computer memory module Function block diagram , a graphical language for programmable logic controller design Functional block diagram , a block diagram in systems engineering Transport [ edit ] Braine-l'Alleud railway station , in Belgium Flemington Bridge railway station , in England Farrukhabad Junction railway station , in Uttar Pradesh, India Fayzabad Airport , in Afghanistan Other uses [ edit ] Far Beyond Driven , an album by American metal band Pantera FBD Holdings , an Irish insurance company Freshfields Bruckhaus Deringer ,

38-446: A British law firm Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title FBD . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=FBD&oldid=1236929587 " Category : Disambiguation pages Hidden categories: Short description

57-488: A focus at a single point. Conversely, a point source at the focus of a parabolic mirror will produce a beam of collimated light creating a collimator . Since the source needs to be small, such an optical system cannot produce much optical power. Spherical mirrors are easier to make than parabolic mirrors and they are often used to produce approximately collimated light. Many types of lenses can also produce collimated light from point-like sources. "Collimation" refers to all

76-421: A misreading of collineare , "to direct in a straight line". Laser light from gas or crystal lasers is highly collimated because it is formed in an optical cavity between two parallel mirrors which constrain the light to a path perpendicular to the surfaces of the mirrors. In practice, gas lasers can use concave mirrors, flat mirrors, or a combination of both. The divergence of high-quality laser beams

95-430: A range of distances within a single lens may be collimation error with the lens, but if such discrepancies occur across several lenses, it is more likely to be the flange focal distance or the ground glass (or both) that are misset. Due to research on optimal flange focal distance settings, it is currently considered better for flange focal distance to be set to somewhere within the film's emulsion layer, rather than on

114-433: A telescope, the term refers to the fact that the optical axis of each optical component should be centered and parallel, so that collimated light emerges from the eyepiece. Most amateur reflector telescopes need to be re-collimated every few years to maintain optimum performance. This can be done by simple visual methods such as looking down the optical assembly with no eyepiece to make sure the components are lined up, by using

133-418: Is an archetypical example. A perfectly collimated light beam , with no divergence , would not disperse with distance. However, diffraction prevents the creation of any such beam. Light can be approximately collimated by a number of processes, for instance by means of a collimator . Perfectly collimated light is sometimes said to be focused at infinity . Thus, as the distance from a point source increases,

152-403: Is commonly less than 1 milliradian (3.4 arcmin ), and can be much less for large-diameter beams. Laser diodes emit less-collimated light due to their short cavity, and therefore higher collimation requires a collimating lens. Synchrotron light is very well collimated. It is produced by bending relativistic electrons (i.e. those moving at relativistic speeds) around a circular track. When

171-457: Is different from Wikidata All article disambiguation pages All disambiguation pages Flange back distance Lenses can be adapted from one mount (and respective FFD) to another. FFD determines whether infinity focus can be accomplished with a simple non-optical adapter. Optics to correct for distance introduce more cost and can lower image quality, so non-optical lens adapters are preferred. A simple non-optical adapter holds

190-428: Is one of the most important variables in a system camera , as lens seating errors of as little as 0.01 mm will manifest themselves critically on the imaging plane and focus will not match the lens marks. Professional movie cameras are rigorously tested by rental houses regularly to ensure the distance is properly calibrated. Any discrepancies between eye focus and measured focus that manifest them­selves across

209-471: Is routinely deployed and is ubiquitous in every particle accelerator complex in the world. An additional method enabling this same forward collimation effect, less well studied, may deploy strategic nuclear polarization ( magnetic polarization of nuclei) if the requisite reactions are designed into any given experimental applications. The word "collimate" comes from the Latin verb collimare , which originated in

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228-472: Is used in front of a detector to allow only photons perpendicular to the surface to be detected. The term collimated may also be applied to particle beams – a collimated particle beam – where typically shielding blocks of high density materials (such as lead , bismuth alloys , etc.) may be used to absorb or block peripheral particles from a desired forward direction, especially a sequence of such absorbing collimators . This method of particle collimation

247-498: The electrons are at relativistic speeds, the resulting radiation is highly collimated, a result which does not occur at lower speeds. The light from stars (other than the Sun ) arrives at Earth precisely collimated, because stars are so far away they present no detectable angular size. However, due to refraction and turbulence in the Earth's atmosphere, starlight arrives slightly uncollimated at

266-549: The ground with an apparent angular diameter of about 0.4 arcseconds . Direct rays of light from the Sun arrive at the Earth uncollimated by one-half degree, this being the angular diameter of the Sun as seen from Earth. During a solar eclipse , the Sun's light becomes increasingly collimated as the visible surface shrinks to a thin crescent and ultimately a small point , producing the phenomena of distinct shadows and shadow bands . A perfect parabolic mirror will bring parallel rays to

285-409: The longer FFD lens the appropriate additional distance away from the sensor or film on the shorter FFD camera. A camera body with a shorter FFD can accept a larger number of lenses (those with a longer FFD) by using a simple adapter. A lens with a longer FFD can be more readily adapted to a larger number of camera bodies (those with a shorter FFD). If the difference is small, other factors such as

304-467: The optical elements in an instrument being on their designed optical axis . It also refers to the process of adjusting an optical instrument so that all its elements are on that designed axis (in line and parallel). The unconditional aligning of binoculars is a 3-axis collimation, meaning both optical axis that provide stereoscopic vision are aligned parallel with the axis of the hinge used to select various interpupillary distance settings. With regards to

323-434: The sizes and positions of the mounting flanges will influence whether a lens can be adapted without optics. Typically, camera bodies with shorter flange focal distance can be adapted more readily to lenses with longer flange focal distance. Lens count doesn't include 3rd party products. All FE lenses (see below) can also be used on APS-C E-mount cameras. Lens count doesn't include 3rd party products. Flange focal distance

342-401: The spherical wavefronts become flatter and closer to plane waves , which are perfectly collimated. Other forms of electromagnetic radiation can also be collimated. In radiology , X-rays are collimated to reduce the volume of the patient's tissue that is irradiated, and to remove stray photons that reduce the quality of the x-ray image ("film fog"). In scintigraphy , a gamma ray collimator

361-398: The surface of it. Therefore, the nominal flange focal depth will be equivalent to the distance to the ground glass, whereas the actual flange focal depth to the aperture plate will in fact be ~0.02 mm less. Collimation error A collimated beam of light or other electromagnetic radiation has parallel rays , and therefore will spread minimally as it propagates. A laser beam

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