Archived posting to the Leica Users Group, 2002/08/28

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

Subject: Re: [Leica] 13% or 23% ?
From: John Collier <jbcollier@shaw.ca>
Date: Wed, 28 Aug 2002 13:15:19 -0600

It is very simple actually, it depends on where the lens is focused as 
to what percentage of the brightline frame area is metered. Naturally 
the metered area on the film does not change just the field of view on 
the film actually covered by the brightlines. 23% would be an arbitrary 
figure used to help you visualize the metered area not a precise 
mathematical representation. The brightlines only show 93% of the film 
area at closest focus so it reasonable to suppose that at common 
distances (5 to 10 meters) the metered area would be close to 23% of the 
brightline area.

John Collier

On Tuesday, August 27, 2002, at 10:05 PM, mjr@grok.org wrote:

> I'm confused by something I read in the manual for my m6 ttl.  It says 
> that
> the metering field is the 12mm spot, or 13% of the negative size, but 
> then
> it also says that the metering field is 23% of what's in the viewfinder 
> for
> any particular lens.  I think that means 23% of what's contained within 
> the
> appropriate brightlines for the lens, which is confirmed by the 
> illustration
> of the different metering fields for the different lens/brightlines.  
> Does
> that mean that the 12mm white spot somehow meters 23% of the field even
> though it amounts to only 13% of the 24x36 mm film size?  What am I 
> missing?

- --
To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html