Any reason this calculation would not work?
EV = log2(composite:aperture/composite:shutterspeed)
Thinking of making EV a composite tag over here.
- J
The ExifTool LightValue tag does this already (including the effect of ISO).
- Phil
EV = log2(F Number^2/Shutter Speed)
LV = 2 x log2(F Number) - log2(Shutter Speed) - log2(ISO / 100)
EV is a common metric now for people I think? I was thinking of presenting both.
It seems EV is also normalized to a 100 ISO (https://photographylife.com/exposure-value#what-about-iso).
I am no expert (I'll probably say this for the rest of my life)! I don't claim to understand this distinction in practical terms.
- J
Interesting article [PDF] (http://www.dougkerr.net/Pumpkin/articles/Setting_Exposure_Ev.pdf)...
- J
Just FYI: (basic math)
log2(F Number^2/Shutter Speed) = 2 x log2(F Number) - log2(Shutter Speed)
EV is not very useful because it only represents part of the picture. It was more useful with film cameras where the ISO was fixed, and is equivalent to LV for ISO 100 as you mentioned.
- Phil
Yes, understood. Thank you!
- J