Primer on C41 w/ Replenishment?

[NortheastPhotographic]

Hi folks!
I'm in the process of starting a little bity film to digital lab here in Portland Maine. I'm picking up a Fuji Frontier SP3000 later this summer, and I'm currently doing a lot of planning and preparation to take on a volume of hopefully 300-400 rolls per month.

I'm used to doing C41 & E6 in a Jobo, but of course when I scale up I'm going to need to shift some to roller transport systems. I've been shopping for a Noritsu V30P or similar, but some bits of info are a little scarce or hard to interpret for someone who's new to roller transport machines...

I'm just looking to know about chemical capacity with replenishment and costs, can anyone give me a rough idea of how these systems work? I'm going to go with an RA machine which I've learned is a bit better than the old SM system, but I'm still learning. We all start somewhere!

Any help beyond the Noritsu PDF would be appreciated. When I'm up and running hopefully later this year I'll announce on APUG of course. There is a hole in the North East USA market for dev/scan labs, and I'm hoping to help fill that.
-Mark

 

[Mr Bill]

I'm just looking to know about chemical capacity with replenishment and costs, can anyone give me a rough idea of how these systems work?

Look up the Kodak Z manuals, they are sort of the user manuals for the processes. (They'll also give the base rates for replenishment)

Basically, though, the developer tank in the processor is filled with a mix of replenisher, water, and a small amount of "starter" solution. (They should have called the starter "slow down" solution; basically it adds "development byproducts" that slow down the development.) When you are running film the machine will automatically add small increments of replenisher, which should be just enough to keep the degree of development constant. But ..It'll never be perfect. You have to periodically check this by processing a preexposed test strip, aka control strip, and compare against the single already-processed strip in the package. You normally use a densitometer to read them, then "make a plot" over time. If the plot is drifting up, then you decrease the replenishment rate slightly, by 10% or so. The other chemicals are replenished in the same general manner, but aren't so sensitive to the rate.

On a different note, do you know how you're going to handle the effluent? This may well be your biggest problem. If it's a "washless" system you'll need someone to haul all the effluent. If not, you'll probably want to put at least the wash water to the sewer; you'll likely need a sewering permit for this. It'll establish limits for silver concentration and specify how this is verified. In the good ole days many places limited silver to crazy low levels like 2/10 mg/liter (your wash water will almost certainly be waaay higher than this). As a note, once you contact someone about this, you'll be on their radar, so make sure your nose is clean, as they say. (There may be a "small generator" exemption in your area, which you would most likely qualify for, but it's something you need to know about.)

Best of luck on your project.

 

[Mr Bill]

I'm going to go with an RA machine which I've learned is a bit better than the old SM system, but I'm still learning.

Well, who's not still learning?

Anyway, details on the C-41RA process can be found in Kodak's Z131_04 document. It doesn't seem readily available anymore, but the guy who runs 125px.com seems to still have a copy up.

Per the Z manual, the RA version is intended to be "washless." It uses the LORR version (note that LORR is a "normal" developer, but formulated to run at half the regular replenisher rate) of C-41 developer replenisher, and the Z manual says rate is 20 mL per roll of 135-24 film (note that is equivalent to about 50 rolls per liter as a point of reference; 36 expo rolls would use about 50% more replenisher).

For the secondary chems: RA bleach replenisher NR = 5 ml per roll of 135-24 film. RA fixer replenisher = 35 mL per roll, and final rinse = 40 mL per roll. So the total effluent, per roll is roughly 100 mL. This sounds pretty low, so better double check the numbers.

As a note, rates are given only for roll size 135-24 which suggests to me that amateur use was intended; pros may be bothered by the washless process (I would be, for important work, unless you could show me image-stability data).

 

[MattKing]

Anyway, details on the C-41RA process can be found in Kodak's Z131_04 document. It doesn't seem readily available anymore, but the guy who runs 125px.com seems to still have a copy up.

At least some of the Z manuals are available from the Kodak Alaris site - the "tree" is "Professional Photographers" - "Labs" - "Chemicals"
http://imaging.kodakalaris.com/professional-photographers/labs/chemistry

 

[NortheastPhotographic]

THanks guys! This was super helpful. When I'm up and running i'll process and scan a roll for ya on the house.

 

[NortheastPhotographic]

I'm sort of thinking now that a Phototherm SSK-8R might be a better option for me in the near term... Not sure if I can still do Flexcolor with replenishers though.