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Prentice's rule, named so after the optician Charles F. Prentice, is a formula used to determine the amount of induced prism in a lens: = where: P is the amount of prism correction (in prism dioptres) c is decentration (the distance between the pupil centre and the lens's optical centre, in millimetres)
Ophthalmology. Esotropia is a form of strabismus in which one or both eyes turn inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. [1] It is the opposite of exotropia and usually involves more severe axis deviation than esophoria.
The Prentice position is an orientation of a prism, used in optics, optometry and ophthalmology. In this position, named after the optician Charles F. Prentice, the prism is oriented such that light enters it at an angle of 90° to the first surface, so that the beam does not refract at that surface. All the deviation caused by the prism takes ...
It is a concept that comes from variable radius plots, or point sampling. It happens when a tree cannot be easily determined as in or out when using a prism or angle gauge. Borderline trees occur only when the distance from the sampling point to the center of the tree is equal to the DBH times plot radius factor (PRF).
A liquid-crystal display ( LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly [1] but instead use a backlight or reflector to produce images in color or monochrome.
In materials science, effective medium approximations ( EMA) or effective medium theory ( EMT) pertain to analytical or theoretical modeling that describes the macroscopic properties of composite materials. EMAs or EMTs are developed from averaging the multiple values of the constituents that directly make up the composite material.
Calculating sheet resistance. In general, the van der Pauw formula cannot be rearranged to give the sheet resistance R S in terms of known functions. The most notable exception to this is when R vertical = R = R horizontal; in this scenario the sheet resistance is given by =
The formula for vertex correction is = (), where F c is the power corrected for vertex distance, F is the original lens power, and x is the change in vertex distance in meters.
SMR index calculation. SMR uses the same first five scoring categories as RMR: Uniaxial compressive strength of intact rock, Rock Quality Designation (or RQD), Joint spacing, Joint condition (the sum of five sub-scores), and; Groundwater conditions.
K correction converts measurements of astronomical objects into their respective rest frames. The correction acts on that object's observed magnitude (or equivalently, its flux).