Nonlinear conversions for photographic exposure scales.
APEX system values (Av, Tv, Sv, Bv, Iv) and EV100/IV100 scales relate logarithmic exposure settings to physical quantities.
Summary
Functions
APEX aperture value to f-number (dimensionless ratio).
APEX brightness value to luminance in cd/m².
EV100 to luminance in cd/m².
f-number (identity, dimensionless).
IV100 to illuminance in lux (cd·sr/m²).
APEX illuminance value to illuminance in cd·sr/m².
Numerical aperture to f-number equivalent (dimensionless).
DIN speed degrees to linear speed (dimensionless).
APEX speed value to ISO arithmetic speed (dimensionless).
APEX time value to exposure time in seconds.
Functions
APEX aperture value to f-number (dimensionless ratio).
APEX brightness value to luminance in cd/m².
EV100 to luminance in cd/m².
f-number (identity, dimensionless).
IV100 to illuminance in lux (cd·sr/m²).
APEX illuminance value to illuminance in cd·sr/m².
Numerical aperture to f-number equivalent (dimensionless).
DIN speed degrees to linear speed (dimensionless).
APEX speed value to ISO arithmetic speed (dimensionless).
APEX time value to exposure time in seconds.