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Disclaimer: this is not exactly an answer to the question, as it doesn't rely on calculation, but experimentation. I used a do-it-yourself approach for checking lens hoods (and vignetting, to some extent), back in the analog times. From cardboard, I cut out a 24*36mm rectangle and glued together a box to hold that cutout at the correct distance from the lens ...


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Angle of view is determined by (real) focal length and sensor/film size. That's your starting point. AoV=2*arctan(d/2f) where: AoV is the Angle of View d is the size of the sensor/film in the direction measured f is focal length (in the same units as d) For a circular hood you would use the diagonal measure of the sensor/film For a "petal" hood ...


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I am looking for such lenses as well. In general putting the aperture at the front or outside is avoided because not good; best is to put the aperture more or less in the center of the objective. With the aperture in front you'll have more aberrations and/or need bigger and more expensive design. Only in two cases the front aperture design is used: if the ...


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It's all about etendue. The maximum amount of light available for an exposure is determined by the system etendue, which defines how spread out the light is. Etendue is defined by the angular extent (apparent/relative size) of the source/subject as seen by the objective element. And it is simultaneously/equally the angular extent of the objective element as ...


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The transition is not as smooth as the calculations may indicate. In the real world there is a disrupting factor known as reciprocal failure ! Which adversely affects the outcome , it reduces the expected amount of light transferable a factor dependent to some extent on the nature of the glass used. Coating the lens and treating the coating with various ...


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The lenses used in VR headsets are for focusing on the screen. It is similar to wearing glasses. It is also similar to the lens in the viewfinder of a camera which has adjustable strength for people with different eyesight. These focusing lenses do not affect the system FOV; unlike a camera lens where the focal length/magnification strength does affect the ...


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