## anonymous one year ago Please what is the Projection Law [Optics]?

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1. anonymous

Lambert's cosine law says that the radiant intensity or luminous intensity observed from an ideal diffusely reflecting surface or ideal diffuse radiator is directly proportional to the cosine of the angle θ between the direction of the incident light and the surface normal.[1][2] The law is also known as the cosine emission law[3] or Lambert's emission law. It is named after Johann Heinrich Lambert, from his Photometria, published in 1760.[4] A surface which obeys Lambert's law is said to be Lambertian, and exhibits Lambertian reflectance. Such a surface has the same radiance when viewed from any angle. This means, for example, that to the human eye it has the same apparent brightness (or luminance). It has the same radiance because, although the emitted power from a given area element is reduced by the cosine of the emission angle, the apparent size (solid angle) of the observed area, as seen by a viewer, is decreased by a corresponding amount. Therefore, its radiance (power per unit solid angle per unit projected source area) is the same. hope this hellps :P

2. anonymous

Thank you. I actually realized that by Projection Law, the teacher was referring to the Lens/Mirror equation.

3. anonymous

you should give me a best responce medal

4. anonymous

$\frac{ 1 }{ f }=\frac{ 1 }{ o }+\frac{ 1 }{ i }$

5. anonymous

tank you