P3D Re: PHOTO-3D digest 2932

[Rob <lilindn@xxxxxxxxxxx>]

Michael A Amundson <Michael.Amundson@xxxxxxx> Wrote:

> I've enjoyed the discussion of the sunny 16 rule and its variations but is
> there a lattitude or altitude that this is geared for? 

Actually, it does assume that the sun is fairly high up in the sky, thus
the often quoted "10 am to 3 pm" or its variants, but if you're way up
north or down south, or if it is winter, you'll need to open the lens a
bit to compensate, even at mid day  (also note that in a world where
politicians tell you how to set your clock, solar "noon" can be 2:00 pm
or even later).

 I've been reading
> Ansel Adams' EXAMPLES and he notes several times the SW light is stronger.
> What about altitude?  I'm at 7,000 feet here in Flagstaff and shoot a lot
> of things on sunny days between 8000 and 10,000 feet.  Any changes?
..
    On a clear sunny day, not much (probably less that 1/3 stop), but of
course, the altitude will indirectly affect this - if Phoenix has low
gray clouds and Flagstaff is above the cloud tops, you'll have more
light in Flagstaff :-)
    What will be different is that you get a lot more ultraviolet in
your sunlight up there, causing haze in your pictures even when your
eyes (blind to UV) see only a clear view.  I would try to use a UV
filter all the time on any camera if I were you.
    Rob
    "Everything I have is Y1.96K compliant"
    "You won't need a UV filter atop Mt. Clemens"


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