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Old June 27th, 2008   #19 (permalink)
MasterZap
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Join Date: May 2006
Location: Eskilstuna
Posts: 70

Name: Håkan Andersson


Sweden 


Cool Re: Exposure expert needed!! Damn mrPhotographic Exposure

Hah

You guys are right, the "camera parameters to EV" calculation is wrong (it uses the ISO backwards). The "EV to camera parameters", however, is correct.

ISO 100, f/16 and shutter 1 should NOT be the same brightness as ISO 50, f/16 and shutter 2, it is shutter 0.5 that is the same.

Remember the "sunny 16" rule: same "shutter speed" as "film speed" for f/16.

So shutter and iso should move in the *same* direction (remember the shutter value is the 1/value measurement) to give "same value".

But the EV is actually calculated wrong for any iso other than 100!

But the EV isn't what is actually used, the "camera parameters" is what is actually used.

Also those wanting the "physical camera" shuold read here

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