It doesn't - and it doesn't try to. It only sets the relative aperture.
Who is to say how transmissive the glass is between different lenses? And
with a manual aperture lens, it could be max f/5.6 or f/2 - the tab would
still be in the same "I am at full aperture" position. Try comparing the
absolute position of the tab on a 55/1.2 and a 21/3.5 - I suspect that they
will be the same.
Piers
-----Original Message-----
From: owner-olympus@xxxxxxxxxxxxxxx [mailto:owner-olympus@xxxxxxxxxxxxxxx]
On Behalf Of Walt Wayman
Sent: 05 December 2003 21:31
To: olympus@xxxxxxxxxxxxxxx
Subject: Re: [OM] OM Pin-hole photography problem - help!
But how's that explain the filter factor thing?
I think the lever position is only for spot readings, so that the exposure
calculation, which is stored and not changed by any OTF readings, can adjust
appropriately from the "wide open" reading to the proper exposure for the
set aperture.
Walt
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
"I was born in the country. I been working in the town.
I been in trouble ever since I set my suitcase down." -- Bob Dylan
---------- Original Message ----------------------------------
From: "Piers Hemy" <piers@xxxxxxxx>
Reply-To: olympus@xxxxxxxxxxxxxxx
Date: Fri, 5 Dec 2003 21:14:57 -0000
>On a T-mount, there *is* one lever sticking out - but in a fixed
>position, transmitting the information to set the 'aperture bias'
>that Daniel spoke of to zero.
>
>Piers
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