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Nikon (under the Mirror-Nikkor and later Reflex-Nikkor names) and Canon both offered several designs, such as 500 mm 1:8 and 1000 mm 1:11. Smaller companies such as Tamron , Samyang , Vivitar , and Opteka also offered several versions, with the three latter of these brands still actively producing a number of catadioptric lenses for use in ...
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A ray diagram for a plane mirror. The incident light rays from the object create an apparent mirror image for the observer. A plane mirror is made using some highly reflecting and polished surface such as a silver or aluminium surface in a process called silvering. [6] After silvering, a thin layer of red lead oxide is applied at the back of ...
Each optical element (surface, interface, mirror, or beam travel) is described by a 2 × 2 ray transfer matrix which operates on a vector describing an incoming light ray to calculate the outgoing ray. Multiplication of the successive matrices thus yields a concise ray transfer matrix describing the entire optical system.
An oblique projection of a focus-balanced parabolic reflector. It is sometimes useful if the centre of mass of a reflector dish coincides with its focus.This allows it to be easily turned so it can be aimed at a moving source of light, such as the Sun in the sky, while its focus, where the target is located, is stationary.
Therefore, as the ray reflects first from side x then side y and finally from side z the ray direction goes from [a, b, c] to [−a, b, c] to [−a, −b, c] to [−a, −b, −c] and it leaves the corner with all three components of its direction exactly reversed. Corner reflectors occur in two varieties.
A convex secondary mirror is placed just to the side of the light entering the telescope, and positioned afocally so as to send parallel light on to the tertiary. The concave tertiary mirror is positioned exactly twice as far to the side of the entering beam as was the convex secondary, and its own radius of curvature distant from the secondary.
The image in a plane mirror is not magnified (that is, the image is the same size as the object) and appears to be as far behind the mirror as the object is in front of the mirror. A diverging lens (one that is thicker at the edges than the middle) or a concave mirror forms a virtual image. Such an image is reduced in size when compared to the ...