say, you have two lenses: A and B.
you mount A. at f/8 and meter shows 1/125. you experimentally find that it overexposes 1/2 ev
you mount B. at f/8 and meter shows 1/100. you experimentally find that it underexposes 1/2 ev
so put these two compensations for THESE exact parameters in the table. voila!
this will work as long as body with A set at f/8 will always meter in the same condition 1/125. the same goes for B.
best, Mishka
J. C. O'Connell wrote:
the problem is that he is making these claims on cameras using TTL metering (open aperture) that assume the selected f-stop and shutter speed combination is not only perfect, but also that changing the speed and aperture settings to what is theoretically the equivalent exposure is also perfect even though a DIFFERENT compensation may needed from the first one. The meter cant be right for both but it indicates the same. JCO
-----Original Message-----
From: Mike Ignatiev [mailto:[EMAIL PROTECTED]
Sent: Wednesday, June 11, 2003 4:45 PM
To: [EMAIL PROTECTED]
Cc: J. C. O'Connell
Subject: Re[2]: Exposure
So make a table:
Lens | Shutter Speed | Aperture | Compensation
-------------------------------------------------
| | |
What's the big deal? I was not saying it's not random. That is irrelevant. What matters is that it's reproducible to withing your tolerances.
If your cammera gives you random shutter speeds at the same position of the dial, or the same lens has different aperture openings at the same aperture setting (over the tolerances) -- that means the equipment is junk.
Mishka
-----Original Message-----
From: "J. C. O'Connell" <[EMAIL PROTECTED]>
To: "Mike Ignatiev" <[EMAIL PROTECTED]>,<[EMAIL PROTECTED]>
Date: Wed, 11 Jun 2003 16:02:13 -0400
Subject: RE: Exposure
shutter speed and aperture variations are random from
stop to stop and speed to speed. There is no way
to "calibrate" them out of the system. Especially if
youre using different lenses which may not match
each other stop for stop.
JCO
