Fp4 really is 125 ISO.

Your personal EI factors in "you".

Your preferences, your eye, your developing technique, your metering techniques, your normal subject matter.

You personal EI should simply be whatever gets you the print you want in the easiest way.

You might try this for a start.

Quote Originally Posted by markbarendt View Post
I'd suggest shooting a single roll of a single subject with a mid-tone reference (a face or gray card or...) under unchanging light starting at maybe 4 stops under and bumping up in 1-stop increments to 5 stops over, 10 shots total. Develop normally then print "to the mid tone" so that the mid tone matches in all ten prints.