Archived posting to the Leica Users Group, 1998/05/25

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: Re: [Leica] sharpness discussion
From: Eric Welch <ewelch@ponyexpress.net>
Date: Mon, 25 May 1998 09:08:34 -0500

At 05:04 AM 5/25/98 +0000, you wrote:
>Can you say that again? Someone should take the non-retrofocus
>lenses and apply the technique to not retro-focus lenses?

Uh, okay, let's see if I can get it right. :-)

No, let me put it this way. Lens building techniques are so sophisticated
these days, that there is essentially no quality different between the two
types. Mike Johnstone said this a couple months ago. So a non-retrofocus
lens could be super, because of the same techniques that make retrofocus
lenses so good these days. But could we see the difference on film? Don't
know.

>Wouldn't be able to meter? What is that about?

If a lens is non-retrofocus, it has to be close to the film. (Retrofocus
was designed, at least in part to get the back element far enough away to
let an SLR mirror swing up). Thus the M6 could not meter, because the back
of the lens is too close to the film to clear the light path to the meter
cell.
- --

=========

Eric Welch
St. Joseph, MO

My Karma ran over my Dogma..