View Full Version : Use of lightmeter as densitometer for Zone system

18-Jul-2000, 16:42
I want to measure negative density with my Minolta incident meter in order to ge t my black&white processing "under control". I took photos of an 18% grey card, bracketed plus minus 5 stops, on Ilford Delta 100, developed in XTOL. I removed the dome from my light meter, placed the film strips on top of the sensor and go t the following f-stop readouts (all at 1/125th second):

Film base: 22/5 (ie. f22 plus 5 10th) 22/4 - 22/0 - 16/4 - 11/7 - 8/9 - 8/3 - 5.6/9 - 5.6/4 - 5.6/0 - 4/8 - 4/5.

How do I convert these numbers to the densitometric scale?

N Dhananjay
18-Jul-2000, 17:06
1 stop = 0.3 density units. DJ

Lukas Werth
19-Jul-2000, 17:04
For this, you must read "Beyond the Zone System" by Phil Davis. It explains the adaption of a light meter as a densitometer, and how to calibrate/use it. It is the best introduction into densitometry I know

Lukas Werth