RE: [Leica] Quantities and qualities (long, but interesting! ;)

["Jonathan Borden" <jborden@mediaone.net>]

Martin Howard wrote:
>
> Steve LeHuray wrote, in part:
> >
> > And to the best of my knowledge
> > every scientific endeavor from Anthropology to cancer to film
> emulsion to
> > snow shovels to yacht design has some baseline numbers attached to it.
> >
>
> Hehe.  Reseach is often divided into two categories: qualitative and
...
>
> You'd be hard pressed to find any respectible
> anthropological/ethnographical
> study reduced to some baseline numbers ;)

	Are you suggesting that neither employs statistics? I don't know much about
either but I recall that there is at least a statistics based branch of
anthropology.

	Every field of science *does* have experiments which produce observations.

... Want an example?  Bokeh was
> nonsense twenty years ago (and still is to some).  It didn't exist.  We
> still cannot reduce it to a simple number, but now there is some doubt to
> the infallibility of MTF testing in capturing all important (and existing)
> characteristics of a lens.
>
	I am not sure the what is called an "MTF" measures both phase and frequency
response but if it does then indeed all the aspects of the lens are captured
(assuming you believe in systems theory). I think that most people have
difficulty looking at an MTF graph and using this to predict "bokeh" but
presumably if you really know your MTF, or conversely have access to
modelling software, those characteristics of a lens which create bokeh are
indeed predicted by its MTF. Of course there remains a role for well written
prose to describe to us mere mortals what an MTF means, presumably why Erwin
is writing a book, and why we might read this rather than the MTF data
available on the web.

Jonathan Borden