On Tue, 24 May 2005, Don Sanderson wrote:
Thanks Paul, I'm just curious as to how one determines where
a number like 4.76 is.
This is the number I get with the 1.7x on a 2.8 lens.
Is it the amount of light one would get at F/4 divided by 1.7,
which puts it nearer 5.6. Or is it closer to 1/2 stop?
You're right, it has no real practical purpose. In real life
I do just like you, partial clicks, EC, etc.
I have one of those inquiring (annoying) minds that likes to
know these silly things. ;-)
Don
Aside from academic interests, it doesn't have much value unless
you wanted to guarantee an identical exposure between shots. Something
like:
f/16 @ 1/100s (0.010 sec)
f/11 @ 1/50s (0.020 sec)
A half-stop in-between would be
f/13 @ 1/66s (0.015 sec)
Yeah, you're right... useless... :)
-Cory
*************************************************************************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
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