pinhole spreadsheet

["Christina Z. Anderson" <zphoto@montana.net>]

If anyone is interested, I can email them a spreadsheet I just created.  It
is a microsoft works file, windows 98, and with the entry of one fstop
number of your pinhole it will work out all the calculations of shutter
speeds for all film ISO's.  For example, my pinhole is f181; I enter that
number, and the formula for the rest is based on  this:

(shutter speed at fstop of denominator)(pinhole f stop squared)
____________________________ (this is a divided sign)
                        fstop squared

Thus, taking the sunny 16 into account with 100 ISO film, it would look like
this:

(1/100)(181x181)
___________________
16 x 16

BUT,  you don't have to do any of this, because the spreadsheet figures it
out.  Now, usually I miss the very obvious, and I am sure there is an easier
and less mathematical way of achieving all this, but what the heck!  All you
have to do is plug in the ISO of your film into your handheld light meter,
get the shutter speed of your light meter to match the ISO, and then
whatever fstop the light meter says (f16,11, etc) you just consult the chart
and you'll have your time.  Methinks I didn't explain this really clearly,
but if anyone wants me to mail it to them, reply OFF LIST.  I was just so
excited I finally figured out how to spreadsheet the calcs that I thought I
would make someone else's life a bit easier!  Oh, and I did test film out
with the times and it works great.
Chris