ilza

@Antisthenes: simple and very convincing! Thanks!

@Kenneth Almquist: Nope.

But: I must confess that I myself might have misunderstood TOO what a “trefoil lens” may mean. I’m used to trefoil KNOTS (as...

… And associativity appears since you can replace (POSITION+CORRECTION1)+CORRECTION2 by POSITION+(CORRECTION1+CORRECTION2) — so you can precalculate CORRECTION1+CORRECTION2.

@Horshack: what you write reminds me the story of Newton and holes in his door. First he had a cat, so made a cat-sized hole to let it walk outside. Then the cat had 6 kittens, so Sir Isaak made...

Apparently, you think that “control over average curvature” implies “some control over curvature”. In my book, there is no implication like this (at least in contexts of aspherical optics).

In...

> “Trust me I know all …”

Then how could you write the s#&$*@ remark above?

@MikeRan: “how can they claim it as useful to make lenses?”

It seems you do not know how precision resistors/etc are made:
 “This one measures 906.83 Ohm; put it into box №907”

(Maybe somebody...

Trefoil means “no axial symmetry”. Try to find an optical application for this!

 (But if an application is found, THEN it is very exciting!)

This one is for people with attention span below 3 sentences: ;–)

I bring it to your attention that my initial post said nothing positive about Sony, and nothing negative about Canon! ¹⁾

 ¹⁾ I...

> “Are you 15?”

Actually, 6.

And, BTW, where were you planning to stick the elegance to?

@MikeRan: > “… how can they claim it as useful to make lenses?”

First of all, they can claim whatever they wish.

Second, as Sandy said, they may control the AVERAGE curvature. For some...

@SandySandy: > “there is nothing stated to say that the curvature of the lens cannot be determined.”

I gave their quote which states exactly this. Surface tension is essentially A NUMBER. Since...

> “… allowing surface tension to do its job.”

My reading: this produces extremely smooth surfaces — but with absolutely no control over the curvature of the resulting element. If so, it is...

One should keep in mind that (with a possible exception of the AMP gate) the transistors on a CAMERA sensor are of negligible size comparing to the sensel itself.

CONCLUSION: (a pictured¹⁾) this...

BTW, are you SURE that “bending” a lens into a meniscus decreases chromatic aberrations and field curvature?

My first foray into “exact optics” was to deduce how “bending” can decrease coma. On...

Thank you very much! I completely missed the Petzval/Laplace connection before! (Double-checking, I found out that in Felix Klein’s fundamental historical treatise, he DIDN’T WRITE ANYTHING about...

This is an absolutely brаindamagеd way to represent data! Usually, Lensrental is doing much better!

With this metric, a device made available in January has 10 times larger weight than a device...

Forget birding/BatIF — with resolution like this, you can go mosquitoing at night!

Just to put this into a photographer’s perspective: how this telescope goes relative to current FF cameras:
 • As telescopes go, this one is pretty lousy optically¹⁾;
 • However, any optically-bad...

@ZeroOne01: ???!!!

Do you realize that this may be the second quarter in a row when Canon’s camera division has¹⁾ historically its worst share of the industry’s revenue? (Below 39%.)

  ¹⁾ Due to...