Is all C-41 chemistry really the same?

I am using Kodak Flexicolor chemistry and monitoring my process with Fujifilm-made control strips. No matter what I do temperature-wise, I can't get density to be the same across RGB/CMY emulsion layers. Blue is always higher than red, and green is lower than red. Earlier I have posted my results here.

My question:

Is Fuji CN-16 chemicals are exactly the same as Kodak C-41? The control strip I am using was developed by Fuji in their CN-16 chemicals. Am I naive to expect Flexicolor to match RGB densities of Fuji's CN-16 within 0.02?

In theory, they should be the same. Remember these chemicals are designed for a replenished process so any slight variances will not matter as the replenisher chemicals rep into the solution tanks.

Have a look here for some guide on control strip reading

Kodak C41 - scroll down to page 3

Fuji CN16 - scroll down to page 29

Steven Lee said:

Am I naive to expect Flexicolor to match RGB densities of Fuji's CN-16 within 0.02?

Click to expand...

IMO the answer is yes.
So long as you are within the control limits (ideally the action limits) you will be ok.

Always remember that you can't read a control strip by eye.

I ran my own minilab for many, many years. I had 3 different C41 processors from Fuji over 35 years. I have used mostly Fuji branded chemicals mainly because of the price. On occasion, I used Champion branded chemicals and swapped between the two. There was no noticeable change.

As I explained in a different post, control strips should be viewed over a period, and plotted onto a graph, that way you can see a drift and make a correction.

Again as with a replenished system, any changes are gradual and easily corrected in plenty of time. Sudden changes or spiles are usually caused by temperature fluctuations or contamination.

I know you are using one shot so extra care must be taken to keep everything consistent
Consistency is the key.

@foc Thank you! I've been studying these docs for a week now, and nowhere I can find a trend where the green goes down and blue goes up :-( At this point I'll just try mixing a new batch of Flexicolor developer...