On 5/16/2011 9:57 AM, Chuck Norcutt wrote:
> I'd still recommend skipping the meter unless you want it for other
> applications... just don't try to use it here. Also, forget auto mode and
> switch to "B" and your watch.
I agree with Chuck. I suggest spending some quality time with Fred Parker's
"Ultimate Exposure Computer". It's all worth
reading, and I remember to do so every so often.
<http://www.fredparker.com/ultexp1.htm#top>
Of particular interest to your problem, giving far more info on practical very
low light EV values than I've seen
elsewhere, is the "Exposure Value Chart"
<http://www.fredparker.com/ultexp1.htm#Light%20Intensity%20Chart>
So, for example, "Night, away from city lights, subject under crescent moon."
is EV -5
If you have a light meter with EV values on it, you may simply set the film
speed and aperture for its lowest setting,
read the EV and double the time for each step down to EV -5.
Or you can work with his "Exposure Factor Relationship Chart"
<http://www.fredparker.com/ultexp1.htm#EXPOSURE%20FACTOR%20RELATIONSHIP%20CHART%20B>
It doesn't go down quite to where you may be going going, but the exposure
math is simple. His chart says -5 EV is 1
min, f5.6, ISO 1600, which is 8 min @ ISO 200
You'll need to add your own reciprocity failure adjustments from the Portra
data sheet.
On 5/16/2011 10:07 AM, Ken Norton wrote:
> I'm also in favor of the Kodak reference book. Can't remember what mine is
> called, Professional PhotoGuide or something like that. In it is a table, and
> circular calculator for determining exposures for various film speeds under
> various available-darkness photographs. It even brings in the subject of
> reciprocity failure.
I have the Kodak Master Photo Guide. Its "Existing Light Exposure Dial" doesn't
go beyond ISO 400, 6 sec. @ f16 for
"Floodlighted Buildings, Fountains, Monuments."
The above guide is more useful, as far as I can see.
No Light Moose
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