Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Photo Image out of focus

Brian Whatcott wrote (in part):

I can think of some helpful conditions - an emulsion latitude
capable of capturing the intensity contributions of several
source contributions - I seem to recall the appropriate measure
of this property is the Hurter-Driffield curve. The fact that
it *is* a curve is unhelpful.

1) What is the Hurter-Driffield curve?
2) The first sentence would be more clear to me if the word
"capturing" were replaced by "distinguishing". Is it not true
that a camera film always captures contributions from several
sources? I must be missing something important; what is it?
Ludwik Kowalski