Response to Converting conventional exposure values to LogE

Try this: Aperture Value (AV)series - AV(f1.0)=0, AV(f1.4)=1, AV(f2)=2, AV(f2.8)=3, AV(f4)=4, AV(f5.6)=5, AV(f8)=6, AV(f11)=7... Time Value (TV) series - TV(1sec)=0, TV(1/2sec)=2, TV(1/4sec)=3, TV(1/8sec)=4, TV(1/15sec)=5, TV(1/30sec)=6.... Exposure Value (EV). EV = AV + TV. The camera settings 1/30sec @ f2 is AV + TV for the respective settings. EV = 6(TV)+2(AV) = 8. To keep the same exposure but change the shutter speed, the formula is AV=EV-TV. Let's change the shutter to 1/2sec. AV=8-2= 6; AV6=f8 This is the old Exposure Value system still found on many light meters. Have fun!

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