HK> Don't worry, I don't believe you will have offended anybody (unless
HK> they're very sensitive)!
:)
HK> My hypothesis as to why (spot) metering of darker faces doesn't work is
HK> as follows. The lightmeter assumes 18% gray reflectance. However, in
HK> this case, the reflectance will be much lower. In an attempt to turn
HK> the image into an 18% gray image, the lightmeter will overexpose.
HK> Therefore you need to underexpose by maybe a stop or two, but I'm
HK> guessing. The opposite is true if you try photographing something
HK> really white eg snow or possibly sand at midday. (I hope I've got this
HK> the right way round...)
But I am already figuring this into my exposure! I wrote in my post
"spotmetering faces and placing them at Zone 6" - that means because
usual caucassian faces are about 1 stop brighter than medium gray (18%
gray) for which meters are calibrated. So I need to open up one stop
from the spotmeter reading. I use a simplified zone scale with the
spotmeter, otherwise, it's almost useless. The problem is, I haven't
figured yet how much the reflectivity of faces of dark skinned people
(especially of certain ethnics, from middle Africa) differs from 18%
gray. I know that for the caucassians, it's Zone 6. But what zone for
them? Zone 4? 4.5? If it was normal portraits, I would be using
incident metering.
Best regards,
Frantisek
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