Search results
Results from the WOW.Com Content Network
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)
Calculation. The free-air gravity anomaly is given by the equation: = (+) Here, is observed gravity, is the free-air correction, and is theoretical gravity.
It can readily be seen that the formula above for motion along the equator follows from the more general equation below for any latitude where along the equator v = 0.0 and = a r = 2 Ω u cos ϕ + u 2 + v 2 R {\displaystyle a_{r}=2\Omega u\cos \phi +{\frac {u^{2}+v^{2}}{R}}}
A dioptre ( British spelling) or diopter ( American spelling ), symbol dpt, is a unit of measurement with dimension of reciprocal length, equivalent to one reciprocal metre, 1 dpt = 1 m−1. It is normally used to express the optical power of a lens or curved mirror, which is a physical quantity equal to the reciprocal of the focal length ...
Prism (optics) An optical prism is a transparent optical element with flat, polished surfaces that are designed to refract light. At least one surface must be angled — elements with two parallel surfaces are not prisms. The most familiar type of optical prism is the triangular prism, which has a triangular base and rectangular sides.
one can calculate the incident angle θ 1 = θ B at which no light is reflected: n 1 sin θ B = n 2 sin ( 90 ∘ − θ B ) = n 2 cos θ B . {\displaystyle n_{1}\sin \theta _{\mathrm {B} }=n_{2}\sin(90^{\circ }-\theta _{\mathrm {B} })=n_{2}\cos \theta _{\mathrm {B} }.}
The formula for minimum deviation can be derived by exploiting the geometry in the prism. The approach involves replacing the variables in the Snell's law in terms of the Deviation and Prism Angles by making the use of the above properties.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
If we take the variance on both sides and use the formula for the variance of a linear combination of variables Var ( a X + b Y ) = a 2 Var ( X ) + b 2 Var ( Y ) + 2 a b Cov ( X , Y ) , {\displaystyle \operatorname {Var} (aX+bY)=a^{2}\operatorname {Var} (X)+b^{2}\operatorname {Var} (Y)+2ab\operatorname {Cov} (X,Y),}
The calculated air mass reaches a maximum of 11.13 at 86.6°, becomes zero at 88°, and approaches negative infinity at the horizon. The plot of this formula on the accompanying graph includes a correction for atmospheric refraction so that the calculated air mass is for apparent rather than true zenith angle.