Originally posted by Kunzite Equivalence is [...] not beautiful at all IMO, and it shouldn't be compared with the f-stop system (which the equivalence tends to destroy).

So maybe, all of us must calm down a bit

Below, I explain the rationale behind calling equivalence "beautiful". There is no reason anybody must share my opinion, but maybe I should explain at least.

Originally posted by johnmflores I get frustrated when people use equivalence as a **weapon**

I do agree entirely.

And now about beauty in science.

I am interested in photography, science and women because I find beauty in all of them. It may be less obvious for science.

I give you one example:

When Dirac in 1928 looked at his equations, he noticed that things are more symmetrical (read beautiful) if he gave ALL possible mathematical solutions a physical meaning. Which led him to predict anti matter. Which actually exists as has been verified years later.

Group theory in mathematics would be another example.

It is a surprising attitude of nature that, if its laws can be made more beautiful, it obeys.

An extremely simple yet very known example is F-Stop, the ratio of aperture and focal length. Because it turns out that a correct exposure (for a given sensitivity of an emulsion) only depends on this ratio, not both focal length and aperture diameter. Which is a simplification and makes the "laws" of photography more beautiful. Nobody today would complain that fstop isn't a lens' real aperture (which is to be measured in mm or inch, like it still is for scopes).

A more recent example now is equivalence. Just like fstop replaces aperture by the ratio of aperture and focal, equivalence replaces image circle, focal, fstop and iso by scaled values, aka "equivalent" focal, fstop and iso. Because it turns out (somewhat hard to prove why I wrote a paper about) that ALL image properties only depend on "equivalent" focal, fstop, iso (and exposure time). And not on sensor size or real focal, fstop, iso. This is a massive simplification of the "laws" of photography. A much bigger break-through than fstop was. And makes the "laws" of photography a lot more beautiful. Something to write home about.

Therefore, somebody saying "equivalence destroys real fstop" is making the biggest joke he can actually make

That's my personal opinion.

Which may explain why I am so passionate about it.