It's a bird

by Vian Esterhuizen

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The 1200mm lens you cite is something of an aberration, since it's built-to-order, not a general-market lens — see Why are some big telephoto lenses so expensive compared to telescopes? and Why are some lenses so expensive?. But the general rule holds true: lenses for DSLRs and most mirrorless cameras are gigantic compared to those in superzoom cameras. ...


No, this is not diffraction. Let's start by recalling how the image is formed by the lens (focused and defocused): Each point of your large aperture lens contributes to just one point of the defocused image: (by the way, this also shows why aperture size affects (de)focus) And what happens if you place an obstacle (your hands) near the lens? Not all ...


Barrel distortion is a form of distortion (not to be confused with other aberrations). It is often found with shorter focal lengths such as the lens in a phone - especially those trying to get the wide rather than narrow angle field of view. This distortion is also often seen with a single element lens, such as those associated with magnifying glass. If ...


The Canon lens has focal length of 1200mm and maximum aperture of f/5.6, whereas the Nikon lens has a focal length (at the long end) of 357mm and maximum aperture of f/6.5. So the Canon lens is longer and has a faster aperture, which requires a larger front element, 214mm vs 55mm. This is a substantial difference and makes the Canon larger, heavier and more ...


Smaller format lenses are eased by having lower maximum image heights and smaller fields of view at the same focal length. Each aberration has explicit field dependencies which describe the rate at which they grow. For the following equations, y is the ray height at the lens and h is image height. Spherical Aberration varies by y3. Coma varies by y2h. ...


No, there is no lens design that allows for sharpening a pinhole image. This is because pinhole cameras by definition don't have lenses. You can replace the pinhole with a lens to get more sharpness with lower f-stops. That's why normal cameras have lenses instead of pinholes. With a pinhole, the sharpness gets better as the pinhole gets smaller, which ...


This can be derived from the basic lens formulas. The lens divides the entire system in two halves: the subject side, with two variables S the real size of the subject, this is what you are looking for s the distance between the subject and the lens, this is the altitude the image side, also with two variables I the size of the subject in the image, ...

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