Wondering anywhere can see the PH of C41

[czygeorge]

As we all know ECN-2 instruction has detailed description of PH of every step the chemical should be at
But C-41(or C41ra I use) only tell replenish rate.I use Jobo so I only replenish Bleach and fixer.And you know the replenish rate of rotary process system is very unknown,so I think maybe use a ph pen to check if the ph correct to see if the replenishment is enough is better.But unfortunately seems like can't find a kodak profile about it

 

[koraks]

Developer pH is nearly always 10.0 to 10.15 unless it's some horribly off-standard chemistry. I did measure the bonavolta chemistry the other day and as I recall it was significantly higher.
For more info, I recently summarized it here: https://tinker.koraks.nl/photograph...lor-developer-formulas-including-c41-and-ra4/
It indicates pH for some DIY developers, including a Kodak developer that should be very close to the Kodak standard.
For Fuji, it's very well documented, but the documentation is sometimes hard to find. You may very well be right in that Kodak doesn't offer much useful information on developer pH for all their products.

I think maybe use a ph pen to check if the ph correct to see if the replenishment is enough is better

To an extent, yes. I don't think it's bullet proof, especially with C41, because not all under-replenishment will show up as pH drift. In other words: even if the pH still checks out OK, you may be under (or over_ replenishing.

 

[halfaman]

There is a document for Kodak chemicals with target pH.

https://125px.com/docs/techpubs/kodak/cis-61-2010_05.pdf

 

[czygeorge]

Thanks a lot Koraks and halfaman, what a precious the information you gave me, it is true that though the cost of bleaching and fixing is very high, but it is not reliable to check whether the supplementary amount is correct only by the pH value, but fortunately, the loss of these two chemicals to process each film is very small

 

[koraks]

You're welcome! Have fun processing lots of C41 film