A question for C-41 developers.

[navilluspm]

I will be shooting half frame in color. I was wondering how long hydrated chemicals last from those powder unicolor press kits. A few months? weeks? days?

(P.S. I was looking for user experience, because I have read the pdf. instructions fromFreestyle).

 

[rogerchristian]

If you mean the powdered or liquid chemistry has been mixed/diluted to working solutions, the generally accepted time, I think, is about a month, when stored under reasonable conditions.

For this reason, most people just take the film to a local processor to develop. cheap, relatively, and the machines are more accurate and consistent, generally, than you can do it at home.

These days, find a store which still does a reasonable amount of color film, so their chemistry is turning over. That it getting harder and harder to do with the reduced film volumes.

 

[navilluspm]

If you mean the powdered or liquid chemistry has been mixed/diluted to working solutions, the generally accepted time, I think, is about a month, when stored under reasonable conditions.

Yes, this is what I meant. Thank you

 

[Keith]

PDF instructions from Freestyle are very pessimistic. My mixed chemicals have processed at least a dozen rolls of film and were mixed several months ago. They still appear to be working fine. I think Petronius has similar experiences.

There was a blog where one guy reckoned his C41 chemicals had been sitting around for a year or so and still worked fine ... he posted the results in fact. I do use airless bottles but that's common sense!

 

[Svitantti]

If you keep them in a tight bottle, air pushed out of them... I'd say months. At least Tetenal Kit's, both E-6 and C-41 keep for a couple months (yes, the mixed working solutions).
Stock solutions for a year or so, opened bottles but air pushed out. This goes for Tetenal that I have experience on.

 

[squirrel$$$bandit]

Mine are going strong after a couple of months. I keep them in airless containers.

 

[navilluspm]

One more question: I noticed that some of you develop more than the recommended number of films per kit. Do you adjust developing times for each roll, or keep it about the same?

(I just got my kits in the mail, and have some rolls ready to process)

 

[Keith]

One more question: I noticed that some of you develop more than the recommended number of films per kit. Do you adjust developing times for each roll, or keep it about the same?

(I just got my kits in the mail, and have some rolls ready to process)

So far after a dozen rolls I haven't changed from the recommended development times and scanning hasn't indicated any need to do so. Colour C41 scans incredibly well and over exposed or underexposed negatives seem to be no real problem in post processing to achieve a satisfactory result.

I'd say judge it by your scanning results as you go ... you should be able to see when you're getting a little under development and you can adjust accordingly.

 

[sienarot]

My chemicals are about 7 months old. I'm probably going to mix up a new batch pretty soon as my last negs looked a little under developed even with compensating a bit of extra development time (but not completely horrible). If I had air tight containers from the start, I'm sure they'd be going a bit longer.

 

[aniMal]

Keep them airtight and they will last longer - and if you put them in a fridge they will last even longer! Should probably be a dedicated fridge due to contamination? Never done that with chemicals myself, but it is the same as with film and most chemical reactions - keep it cool and the changes takes longer...