what I'm trying to do is to perform the test to customize film speed and development
there are many methods, I decided to try the method described in the book "Way Beyond Monochrome" chapter Creating a Standard (page 211) + excel spreadsheet provided by the book author at http://www.darkroomagic.com/DarkroomMagic/Darkroom.html. There are 3 methods suggested there. I have a medium format calibrated Stouffer 31- step tablet, therefore I decided to try the method called Elaborate and Precise. I also have older densitometer which fortunately agrees with calibrated stouffer for visual, and blue channels within 0.02.
I primarily take photos in sunlight that's why I decided to use sunlight to do the test but...
Problem I faced was that I was not able to run the full test (5 rolls of film) because light at my location (due to trees, windows position etc) was changing, even during the same roll of film.
So I came up with the idea to use flash with gel (to match 4500K) instead of sunlight. However in WBM page 218 we can read that "...Film has a different sensitivity to different wavelengths of
light. Therefore, select a light source with a color temperature representative of your typical subject matter and setup. In other words, use daylight or daylight bulbs if you are a landscape photographer, and use photofloods or flashlight if you mainly work in the studio".
That made me think if simple gelling flash to light color temperature of daylight will do the trick and it wont negatively affect the tests.
That's why I decided to ask experts for help.
Last edited by wiedzmin; 03-08-2013 at 08:23 PM. Click to view previous post history.