M6 metering: area and light response

[Charles E. Dunlap <cdunlap@rupture.ucsc.edu>]

Reading through my nifty M6 brochure (late model, no serial number, no 
focussing tab) I ran accross a couple of interesting bits of information 
on the M6 meter.

1) The meter reads a circle with diameter 2/3 the length of the short 
side of the frame line for the lens in use. Switching to the frame lines 
of the next longer focal length lens might help you visualize this area, 
but it doesn't change what is being metered.

2) The meter cell has a light filter in front of it that transmits light 
as the eye sees it. This is all that the brochure says, and it leads to 
my question:

Does the M6 meter effectively filter out infrared light? 

I know from experience that my Nikon's meter underexposes grass because 
it reacts to the strong IR light coming off the leaves. If the M6 meter 
were insensitive to IR light this might account for part of people's 
claims the it is uncannily accurate.

-Charlie

Charles E. Dunlap
Earth Sciences Dept.
University of California
Santa Cruz, CA 95064