P3D Questions on Sunny 16

[Paul Talbot <ptww@xxxxxxxxx>]

DrT writes in connection with the Sunny-16 table:

> PS. I think most errors are in overestimating the amount of light
>     present.  For example, who might have thought that the proper
>     exposure for "forest shade" is six stops below sunny day...

I find one of the hardest parts of using Sunny-16 is making
sense of some of the brief descriptions.  What is "forest
shade?"  The light in many forests is sort of a filtered
or "speckled" sunlight.  In other forests, perhaps no direct
sun reaches the subject.

One thing that surprises me is that "tree shade" (what kind
of tree shade?) is two stops darker than "heavy overcast,"
and 1 stop darker than "dark shade!"  How could that be?
Would not the shadow of a skyscraper qualify as "dark
shade?"  Is the shade of a tree a full stop darker?  Then
what if you are under a tree on an overcast day?  The tree
doesn't cast a shadow.  Is it still darker than than the
-3 recommendation for heavy overcast skies?  If so, by
how much?

Finally, the chart suggests that 3 stops is the most you
would ever have to open up when shooting outdoors in the
open during the "working hours" of Sunny-16.  I find that
hard to believe.  I'm sure I've metered darker conditions
than that--possibly much darker.  Was my metering all
wrong, or is there something missing in the descriptions
in the chart (partially reproduced below)?

+1 1/150 @ f16  sand or snow under bright sun
 0 1/100 @ f16  *sunny day rule* (front bright sunlight, distinct
shdws)
-1 1/100 @ f11  hazy sun, soft shadows, side lighting
-2 1/100 @ f8   cloudy & no shadows, sunset w/sun, moon
-3 1/50  @ f8   heavy overcast, bright shade
-4 1/50  @ f5.6 dark shade, twilight at sunset
-5 1/25  @ f5.6 Skyline just after sunset, tree shade
   ** Limit of hand-holding, use tripod for the following **
-6 1/5  @ f8    N. window light, forest shade, shows w/carbon-arc
sptlght

Paul Talbot


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