Watching Over

by Vian Esterhuizen

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PF and DO terminologies are nominally interchangeable; Canon holds patents for Diffractive Optics lenses: .. while Nikon has "Phase Fresnel" patents: I believe that their technologies are ...


Actually, according to Ken Rockwell, the optics in the 40mm Nokton f/1.4 might actually be much better than the optics in the 35mm Nokton f/1.4. 35mm Review gives 1 star for optics quality 40mm Review gives 3 stars for optics quality So, while I can not comment on the cause of the price difference between the two lenses, it certainly doesn't seem ...


These lenses work basically like a magnifying glass (or reading glasses) in front of the lens. In fact, not just basically — actually exactly. That has the effect of decreasing the distance from the back of the lens to where an in-focus image is formed, which gives the lens more freedom to focus more closely. And focusing more closely is inherently all ...


Because most smartphones without an additional external macro lens do not have optical systems capable of taking photos at close enough minimum focal distances to produce macro photographs. Even if you define macro as the equivalent magnification needed for the tiny sensors found in most phones to produce a print comparable to one made when the image of a ...


You are effectively asking about the geometric behavior of light...rays extending from points, passing through lenses, being bent, and focusing somewhere. This is a very well understood model of the behavior of light, and there are some excellent resources out there that cover the topic. It is much too involved to cover here, so I'll just quote from a couple ...


I think I get what you are asking - we can assume the sensor limits resolution, and if we know magnification of the system we can then relate this to an object space resolution limit. Your approach is going in the right direction, but you should use the rayleigh criterion as the definition of resolution on the sensor (this assumes diffraction limit. ...


It seems that you are looking for the resolution of a given optical system. If this is true then such estimation is rather complex as it involves both the resolution of the lens and the resolution of the sensor. These computations take into account basically the lens quality and the apperture, the size and density of the sensor and more. In addition, to be ...

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