- Nov 17, 2004
- Multi Format
Is that polynomial interpolation Lee?
It's a logarithmic curve. It seems to do a good job with almost any typical film development for gamma vs. developing time. I've used it with data having 5 or more observations and it holds well.
in this case
a = 14.5205569019166
b = 16.2429697851392
x = gamma
y = development time in minutes
I use http://scidavis.sourceforge.net/download.html for this (and investigating reciprocity). A spreadsheet should do as well. Just plug in the data, chart it, then click on the curve in the chart and add a trend line, and have it display the formula.
I have gotten grief for showing the math before on APUG, so didn't post it in the original. Some people like black box solutions. And I won't respond to comments on significant digits in the variables above either, it's cut and paste from a computer program.