"Kérlek hagyjatok meg tudatlanságomban és tévedésem fertőjében"

Csak ne fertőzz meg másokat. Egyetértek DIE_ROBOTER-rel (1333)...

Mathematically, the two definitions for EV are calculated as follows:

   For how much light will be admitted to the film by aperture and shutter speed:

      EV=AV+TV; AV is Aperture Value, and TV is Time Value

      AV=log₂(N²); N is the aperture f-number

      TV=log₂(1/t); t is shutter speed in seconds

   AV=0 for an aperture of f /1, and TV=0 for a shutter speed of 1 second.

   For how much exposure is required by subject luminance and film speed:

      EV=SV+BV; SV is Film Speed Value, and BV is Brightness Value

      SV=log₂(0.32S); S is the film ISO (ASA) speed rating

      BV=log₂(B); B is subject luminance in foot-Lamberts

   SV = 0 for an ISO film speed of 3.125, and BV = 0 at 1 foot-Lambert of luminance.

*vél*