[Leica] Leica lenses

["Kotsinadelis, Peter (Peter)" <peterk@lucent.com>]

I'll ask Bill if he would be willing to put some notes down for me to pass
on to the LUGs.  When he started getting detailed into deffraction theory I
was lost, he brought it down to a level I could better understanding.  Bill
is a Leica user, so he does appreciate their optics.  I like Bill because he
is so honest.  If it stinks, he will tell you. If its great, likewise.  

Peter K

- -----Original Message-----
From: dmorton@journalist.co.uk [mailto:dmorton@journalist.co.uk]
Sent: Friday, January 15, 1999 9:02 PM
To: leica-users@mejac.palo-alto.ca.us
Cc: dmorton@journalist.co.uk
Subject: Re: [Leica] Camera Bag for an amateur photographer with M6's


Patrick Giagnocavo wrote:
> 
> I would like to hear more about Bill Maxwell's views on this.  This
> does sound interesting; what he seems to be saying is that the light
> transmission which is assumed to be roughly equal for a Nikon lens
> and Leica lens at the same f-stop

Let's pause there. Light transmission is equal for the same *T* stop. 
f-stops are a geometric concept.

> actually varies with the amount of
> light going through the lens?  That is, x amount of light is
> transmitted for the part that has the most brightness, but those
> parts of the scene that are dimmer can vary?

If that's what someone's saying - that Leica lenses are non-linear [*] - 
I'd be *fascinated* to hear the explanation (and not a little sceptical).

D

[*] to be clear here, I mean non-linear in amplitude response, I'm not 
referring to geometric properties.