Which Kodak C-41 chemicals for Jobo?

[Dug]

Can anyone comment on using the different Kodak products in a Jobo?

Specifically, I picked up some Kodak C-41 SM developer (175-6337) that you can mix up in 2L batches. Can I substitute this developer and use the other standard Flexicolor chemicals? (I do one-shot processing) According to the data sheet the C-41 SM developer time is 3:15 (same as the others).

I also have C-41 RA Fixer/Replenisher (162-6571). It is for a rapid C-41 process. Can I use this fixer in a "regular" one-shot C-41 process in a Jobo? I do 4 rolls/500ml batches.

Kodak warns against doing such naughtiness, but I am between the capacity of 1 liter kits and the larger sizes and got these items from Rainier Photographic, who closed their doors for good last Saturday.

I plan on trying it on test rolls and will publish my findings.

 

[Bob Carnie]

Sorry Dug,, I can't help you on this.

 

[Photo Engineer]

The bleach and fix of any C-41 can be mixed with any C-41 as long as the times are appropriately adjusted based on the particular instructions. Washes may have to be adjusted accordingly as well.

You can even omit the starter in the bleach and fix and see little problem but you may have to adjust time upwards a bit. You can go overtime in the bleach and fix with no harm as they go to completion. You may have to adjust wash times upwards to compensate.

The restrictions on stabilzers or final rinse that I posed earlier apply as well, particulary as regarding film age (generation).

The final wash before the stabilzer or final rinse must never be colored, nor carry colored material into the final rinse or stabilzer. If it does, image stability will suffer in some way or another. The final solution should never take on a pink or red or brown color.

You must never wash after the stabilzer or final rinse!

The color developer should work as advertized as long as mixing instructions and use of starter or no starter as recommended for your kit are adhered to. I never heard of the developer that you referred to, but it should work with no problem.

Current chemical preparations for Kodak are now done by another company, but using Kodak facilities in Rochester. This was posted earlier on APUG.

PE

 

[Dug]

Thank you PE - Your guidelines are very helpful for us to understand some of the engineering behind these products and procedures

The C-41 SM developer looks to be a simple repackage of standard developer chemistry to further simplify the process of preparing chemistry for smaller commercial machines. I will mix as instructed and develop for the standard 3:15 @ 38 deg C.

The C-41 RA fix/replenish is a little confusing: RA stands for "Rapid" and it is supposed to be used for a shorter period of time with no wash required. (I don't know why one would place "RA" in the middle of the name of a C-41 process!) I plan on using it for the standard 6:30 @ 38 deg C. If fix is one of the processes that goes to completion it should be OK at a standard instead of "Rapid" time. I will follow with a final rinse.

I'll let you all know how it goes.

Doug

 

[Photo Engineer]

I'm familiar with the RA fix and AAMOF worked on an RA BLIX for C41 in the 60s before the process came out. If you want archival prints, you must wash after the C-41 RA fix, and this fix is more critical for time as it will increase swell and soften film. You must also use a final rinse.

This was intended for machines with no wash or low wash rates and disposable negatives (the customer gets only digital images on CD). With no wash following the fix, the images are not all that stable IMHO.

PE

 

[Discpad]

The bleach and fix of any C-41 can be mixed with any C-41 as long as the times are appropriately adjusted based on the particular instructions.

No! You shouldn't mix C-41RA fix with conventional fix!

Cheers!
Dan Schwartz

 

[Photo Engineer]

Dan;

I said any C41 fix can be mixed with any C41 fix for use in a Jobo as in the original question. This is correct. This will work. I assure you, as long as you use the time adjusted for the mixture.

PE

 

[Discpad]

Ron, I can see someone trying to mix sodium thiosulfate fixer into the C-41RA ammonium thiosulfate solution...

 

[Photo Engineer]

Yep, but it works. The C41 fixer uses Ammonium thiosulfate as does the RA fixer, but the RA fixer has added ingredients.

In any event, you can mix sodium and ammonium and RA + C41. The pH is what is critical and both fixers are at about the same pH.

As long as you use the standard C41 times or the longest times recommended by the slowest fixer, it will work just fine!

No problem whatsoever.

PE