
@stefpix > I am wondering if Sony's new lenses are designed by cutting > corners and they all focus shift Focus shift is essentially caused by spherical aberration (SA). A lens subject to...

@Rishi > The lens also stopped down even for AFS/initial acquisition > if you pointed it a brightish scene  as if the camera is > afraid of letting in too much light, which makes no sense In...

. > That's a 50mm lens, a standard, boring focal length. [..] > it's something that you can put on the camera and take > everywhwre with no high expectations. The kind of fashionably dismissive...

Simple Definition of compliment : a remark that says something good about someone or something Simple Definition of complement : something that completes something else or makes it better As to ...

Note that discussions about the aperture bahaviour of this lens based on Rishi's interesting, but necessarily quick handson are fairly irrelevant. Sony explicitly states that the A7R2 must be...

../.. As light field photography demonstrates, imaging systems are becoming, more and more, computational systems. An important theoretical limit of such systems is that the mapping mechanism...

Your assertion: "there exist bijections form R^3 to R^2, you did not have to go to countable sets" My reply: Such bijections are theoretical constructs — e.g. fractal — that are not computable,...

Your assertion: "On a more mathematical note, R^2 and R^3 are not isometric, and there is nothing we can do about that." My reply: As explained above, nothing prevents a 2D surface from being...

Your assertion: "There is no projection that would preserve distances  it is a trivial thing to figure out. All points on any radial way, for example, will be projected to one, which means zero...

Your assertion: "The same "distortion free" lens makes your head look like a head of a Martian near the edges and does not preserve angles or ratios of angles/sides not parallel to the image...

../.. Note that, say, a 24MP fullframe sensor has a pixel pitch of about 6 microns — i.e. about six thousand nanometers. As explained above, there exist optical systems that can project a picture...

Nope. It's you who are a bit out of your depth, as demonstrated by your shallow, sweeping statements. Your assertion: "there is no such thing as a distortion free lens or a lens with...

On a more mathematical note, a projection is a mapping. Furthermore, it's far from established that the fabric of the Universe has the cardinality of the continuum. At a microscopic scale — e.g....

The angles and distances of 3D objects can be preserved by photographing them using a bitelecentric lens, as used e.g. in machine vision applications. With such a lens, given that the entrance...

../.. It's thus much more rational for a lens designer to allocate the "correction budget" — i.e. ther finite number of available lens surfaces and degrees of freedom in an optical design — to...

../.. Examples of wellcorrected, essentially distortionfree lenses include e.g. the ApoNikkor photoengraving process lenses. Other examples include the reduction lenses in the scanners that...

Assume the subject is a 2D flat plane — e.g. a brick wall — and that the camera is parallel to said wall. Assume we choose, on this wall, four distinct points, which we'll name A1, A2, B1 and...

../.. Volume anamorphosis will NECESSARILY happen when mapping / projecting a 3D subject to a 2D surface, like a film or an image sensor. This is a bit similar to the "distorsion" which occurs...

Take a picture of a flat brick wall with a wellcorrected — i.e. distortionfree — wideangle lens, and the bricks at the edges of the picture should have the exact same size as in the center. ...

A simplistic opinion, which overlooks the fact that any decent, wellcorrected photographic lens is typically constructed from glass elements and groups, assembled using positioning rings, shims,...
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