Quote Originally Posted by wiltw View Post
Aim your EP1 at an 18% grey card that fills the view, and note the reading. Now, in the same light, aim your Gossen meter in reflected metering mode at the same grey card and note its reading. Now, in the same light, aim the incident light hemisphere of the Gossen meter toward the camera lens position, and note its reading. If the three are not within about 0.66EV of each other, one of the meters (likely the Gossen) is in need of calibration.
Picked up an 18% gray card yesterday and performed your test with direct sunlight ~7:15 a.m. and got these results:

E-P1 = 1/60 sec @f/16 (does not provide 1/3 stop detail)
SBC reflective = 1/60 sec @f/16 +2/3
SBC incident = 1/60 sec @f/16 +1/3