Search results
Results from the WOW.Com Content Network
When dealing with a beam that is nearly parallel to a surface, it is sometimes more useful to refer to the angle between the beam and the surface tangent, rather than that between the beam and the surface normal. The 90-degree complement to the angle of incidence is called the grazing angle or glancing angle. Incidence at small grazing angles ...
An 1837 view of the history of "the Law of the Sines" [5] The law was eventually named after Snell, although it was first discovered by the Persian scientist Ibn Sahl, at Baghdad court in 984. [6] [7] [8] In the manuscript On Burning Mirrors and Lenses, Sahl used the law to derive lens shapes that focus light with no geometric aberration. [9]
Briefly, imaging [6] involves tilting the incident illumination until a diffracted, rather than the incident, beam passes through a small objective aperture in the objective lens back focal plane. Dark-field images, under these conditions, allow one to map the diffracted intensity coming from a single collection of diffracting planes as a ...
An illustration of the heel effect in an x-ray tube. In X-ray tubes, the heel effect or, more precisely, the anode heel effect is a variation of the intensity of X-rays emitted by the anode depending on the direction of emission along the anode-cathode axis.
When a ray encounters a surface, the angle that the wave normal makes with respect to the surface normal is called the angle of incidence and the plane defined by both directions is the plane of incidence. Reflection of the incident ray also occurs in the plane of incidence.
In professional productions, the applied 180-degree rule is an essential element for a style of film editing called continuity editing. The rule is not always obeyed. Sometimes a filmmaker purposely breaks the line of action to create disorientation.
Screen direction is the direction that actors or objects appear to be moving on the screen from the point of view of the camera or audience. A rule of film editing and film grammar is that movement from one edited shot to another must maintain the consistency of screen direction in order to avoid audience confusion.
A spatial jump cut at 0:05 seconds from It's a Wonderful Life (1946) in which James Stewart's character answers a telephone.. A jump cut is a cut in film editing that breaks a single continuous sequential shot of a subject into two parts, with a piece of footage removed to create the effect of jumping forward in time.