How do we ensure you’re getting consistent film developing every time?
Every morning we run a control strip through our C41 and E6 machines to ensure our chemistry is within the acceptable reference values provided by Fujifilm.
First we need to grab a Fuji test strip. Once the machine is warmed up we run the test strip through.
Once the test strip is dry we run it through x-rite 880 to get the readings. The software then automatically calculates and updates the system.
Fuji provides references. You want your chemistry readings to be within a range of the reference values. If it’s not then you need to trouble shoot your chemistry which is an entirely different issue.
We have updated the C-41 system with software that makes calculating these values a breeze, however our E6 machine is still calculating the old fashion way – by entering the readings and calculating the ranges by hand.
We take the test strip, place it into the x-rite densitometer, enter the values, and manually calculate the range.
But what do these values mean?
There’s a much larger map of process controls that measures a broader range of data but the industry has narrowed it down to these 5 points and call it a process control strip at which we run for e6, color, b&w.
Y-patch is for the fixer bleach activity. If you were ever beyond the standard parameters then you know you have a bleach/fixer problem.
D-max or max density is the highest optical density the film can produce in the developer. It reflects how dark the darkest patch gets after processing.
HD or high density is to check the maximum dye-forming ability of the developer. If HD values are off, it usually means developer activity or temperature issues.
LD or low density checks the developer’s ability to form the correct density in lightly exposed areas.
D-min or minimum density represents how clear the unexposed areas of the negative are. If D-min is too high, it often indicates chemical contamination, light leaks, or exhausted bleach/fix.
