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Shutter speed and aperture functions

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This commit is contained in:
Daniele Verducci 2024-04-30 07:52:16 +02:00
parent 5e557cc29f
commit 5273206c33
1 changed files with 7 additions and 2 deletions
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9
src/ev_calculator.py
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@ -1,4 +1,4 @@
from math import log from math import log, sqrt
''' '''
This class does all the required math. It is based on the Wikipedia page This class does all the required math. It is based on the Wikipedia page
@ -17,8 +17,13 @@ class EVCalculator:
K = 12.5 # TODO: Add to settings? K = 12.5 # TODO: Add to settings?
def luxToEV(lux: float) -> float: def luxToEV(lux: float) -> float:
# Wikipedia (https://en.wikipedia.org/wiki/Exposure_value#EV_as_a_measure_of_luminance_and_illuminance) # Wikipedia (https://en.wikipedia.org/wiki/Light_meter#Exposure_equations)
# says E = 2.5 * (2^EV), so the inverse is EV = ln(2*E/5)/ln(2) # says E = 2.5 * (2^EV), so the inverse is EV = ln(2*E/5)/ln(2)
return log(2*lux/5, 2) return log(2*lux/5, 2)
def calcShutterSpeed(isoSpeed: int, lux: float, aperture: float):
return ((aperture^2)*K)/(lux*isoSpeed)
def calcAperture(isoSpeed: int, lux: float, shutterSpeed: float):
return sqrt(lux*isoSpeed*shutterSpeed/K)