This is driving me crazy! 
We will use the Sunny 16 rule as a base. So 125 ISO film, 125/th of a second at f-16.
I take a grey card reading in direct sun, My LunaPro is within 1/3 of a stop of Sunny 16.
My serviced Soligor spot meter reports a full 5 stops less, 1/4 second at f 16.
I've just bought a 'blad PME 3, and to my amazement it reports the same as the Soligor.
What accounts for this? The Soligor is wrong - when I expose at what it suggests I get a dense dark square of film.
I know I can adjust my my ISO setting to make the PME and Soligor report correctly.
I just don't understand why the discrepancy?
Any thoughts? I can assure you I am using all meters correctly.
Allan Greenier

We will use the Sunny 16 rule as a base. So 125 ISO film, 125/th of a second at f-16.
I take a grey card reading in direct sun, My LunaPro is within 1/3 of a stop of Sunny 16.
My serviced Soligor spot meter reports a full 5 stops less, 1/4 second at f 16.
I've just bought a 'blad PME 3, and to my amazement it reports the same as the Soligor.
What accounts for this? The Soligor is wrong - when I expose at what it suggests I get a dense dark square of film.
I know I can adjust my my ISO setting to make the PME and Soligor report correctly.
I just don't understand why the discrepancy?
Any thoughts? I can assure you I am using all meters correctly.
Allan Greenier
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