At 12:45 AM 8/23/2002 -0400, you wrote:
> I was just wondering how long to expose at bulb for a shot of the
>moon....between 1/2 & full (moon that is) :-p
The Sunny 16 rule is a good starting place, but a better starting place is
a good astrophotography book like "Astrophotography for the Amateur" by
Michael Covington, ISBN 0-521-62740-0.
There is a specific formula:
f^2
time (in seconds) = --------
SB
S is the film speed. B is a constant that indicates the brightness of the
object: 7 for a thin crescent moon, 16 for a wider crescent, 32 for a
half, 70 for a gibbous, and 180 for a full moon.
f is the fstop of the camera. So at f/16 ISO 400 works out to 1/281th of
a second. Not quite the Sunny 16's 1/400th.
His book also provides a handy chart of exposures based on film speeds and
apertures so y ou don't have to do the math. If you are in any way
interested in photographing the night skies, this book is a must.
Thanks,
Rob
--
Rob Miracle
Photographic Miracles
203 Carpenter Brook Dr.
Apex, NC 27502
http://www.photo-miracles.com
