Agreed ... factors of 2 are easy but what if you wanted a factor of 4
or 6 or 75?
I will agree again that is is academic but in certain obscure and
unanticipated applications it might be useful to know this if you want
to determine a specific
f number rather than just guessing at it. The question was asked in an
academic
setting - part of the overall technical education of photo technology
students.
Andy
PS: Interestingly ... most students here don't know what a
photographic enlarger
is or what a light meter is either! The digital age is upon us! ;) <-
wink!
On Jan 21, 2011, at 10:12 AM, Lew wrote:
Yes, but a quick look at any lens or light meter tells you just as
much without any calculations at all. Each stop signifies a factor
of 2, so to get 4x the amount of light, click over 2 stops & you're
done. Teaching a student all this math (if this is what the thread
is about, I wasn't in on the beginning) is very academic. It's not
anything a photographer with a camera in hand would ever do.
