Can I split CineStill dry C-41 chemicals by weight to mix smaller batches?
Asked 7/13/2024
2 views
2 answers
0
I only process C-41 occasionally, so liquid concentrates tend to expire before I use them up. I’m considering buying a precise scale and using a CineStill dry C-41 kit, weighing out only enough powder to make about 500 ml at a time. Are these dry chemicals mixed homogeneously enough that dividing the powder by weight is reliable, or should the full package always be mixed as directed?
Originally by bmargulies. Source · Licensed CC BY-SA 4.0
bmargulies
1y ago
2 Answers
3
I have never tried, but relatively common sense would indicate that you should not do so.
Ilford warns against such practice in the instructions for all their powdered developers: 'Always make up the developer stock solution to the volume stated on the pack, do not attempt to prepare smaller solution quantities by using fractional parts of each powder.' I did not find anything about this mentioned in the Cinestill instructions, but they are relatively sparse and not as verbose as the Ilford instructions.
The reason is simply that mixed powdered chemicals are in general not homogeneous. Due to particle segregation, smaller grains and more dense substances will sink to the bottom and larger grains and less dense substances will float on the top. You can not expect the ratios of each component to stay constant if you split up a powder mix into several portions.
Originally by jarnbjo. Source · Licensed CC BY-SA 4.0
jarnbjo
1y ago
0
Generated from our catalog & community — verify before relying on it.
Generally, no—you should not assume a dry C-41 kit can be accurately split by weight unless the manufacturer explicitly says it is designed for that.
The main concern is powder segregation: during shipping and handling, different components can separate because particles vary in size and density. That means one scoop or partial weight from the package may not contain the correct chemical ratios, even if the total package was formulated correctly. This is why some manufacturers of powdered photo chemistry specifically warn against mixing partial quantities from a package.
One community response reported no known issues, but that is anecdotal and not strong evidence that the mix is reliably homogeneous.
The safer approach is to mix the full kit to its intended volume, or buy the individual chemical components separately if you want to make smaller, exact batches. If CineStill’s instructions do not explicitly allow dividing the dry contents, it’s best not to rely on it.
Recommended products
UniqueBot
AI1y ago
Your Answer
Related Questions
Can you mix only part of a powdered photo chemical kit, or should you mix the whole batch?
Can Kodak commercial C-41 chemicals be used for home film developing?
Can Kodak Flexicolor SM Tank Final Rinse be used as a stabilizer for C-41 film?
Does developer volume change chemical capacity, or just the minimum needed to cover the film?
Does slightly over-diluting Kodak D-76 stock solution matter?