How to reuse RA4 Developer?

So I’ve been using ra4 developer as a one shot but just been putting the used developer in another bottle, is there anything I can add to the used developer to reactive it? Starter or replenisher? I have both

Kodak Ekatcolor Starter
Champion Replenisher

Thank you friends!

You add replenisher at the rate of the manufacturer's specification, so depending on the square footage of paper you've processed in it. I usually replenish a little more to compensate for the oxidation of a small-scale operation; this will especially be relevant if you use open trays or even drums. Do not add starter to the already used developer.

Starter is only used to make the initial processing volume. The last time I used starter in my darkroom was around 1.5 years ago or maybe even longer. I always put my used developer back into a couple of bottles at the end of a session and replenish depending on how much I've printed.

When I did RA4 with a Jobo processor ( a CPE as it happened) I used to fill those 600 ml containers that were made for sitting in the heated water bath of the Jobo and each print needed about 140ml in the drum. So I poured the used developer back into the 600ml and then re-used it for the next print. There was of course a limit to how many prints could be done that way but it was a lot more economical than dumpling 140 ml each time

What I cannot recall is whose RA4 chemistry it was which could be used that way but I'd assume that the principle would apply to any RA4 chemistry

Others may be able to confirm this

pentaxuser

koraks said:

You add replenisher at the rate of the manufacturer's specification, so depending on the square footage of paper you've processed in it. I usually replenish a little more to compensate for the oxidation of a small-scale operation; this will especially be relevant if you use open trays or even drums. Do not add starter to the already used developer.

Starter is only used to make the initial processing volume. The last time I used starter in my darkroom was around 1.5 years ago or maybe even longer. I always put my used developer back into a couple of bottles at the end of a session and replenish depending on how much I've printed.

Click to expand...

This is what my replenisher says online and my bottle, I’m developing 8x10

Sorry this kinda stuff confuses the hell outta me

legstowalkmyself said:

This is what my replenisher says online and my bottle, I’m developing 8x10

Click to expand...

The 'tank mix' is if you mix a new volume of developer, so when you basically start over with nothing. If you want to replenish that developer after it has been used once (or multiple times), you follow the instructions to mix the 'replenisher'. It uses less water and no starter.

So you start by mixing a 'tank mix' the first time only. Let's say you mix 2 liters or so.
Then you start using those 2 liters. After each run you dump the used developer back into the 2 liter bottle with the rest. Periodically you dump some of the used developer and add replenisher (mixed as per the 'replenisher' instructions, NOT the 'tank mix' instructions). The amount of replenisher you have to add depends on how much paper you've processed since the last replenishment (or since mixing fresh dev if it's the first time you're going to replenish).

So 'tank mix' you use only the first time and then you keep revitalizing that same developer volume using replenisher.

koraks said:

The 'tank mix' is if you mix a new volume of developer, so when you basically start over with nothing. If you want to replenish that developer after it has been used once (or multiple times), you follow the instructions to mix the 'replenisher'. It uses less water and no starter.

So you start by mixing a 'tank mix' the first time only. Let's say you mix 2 liters or so.
Then you start using those 2 liters. After each run you dump the used developer back into the 2 liter bottle with the rest. Periodically you dump some of the used developer and add replenisher (mixed as per the 'replenisher' instructions, NOT the 'tank mix' instructions). The amount of replenisher you have to add depends on how much paper you've processed since the last replenishment (or since mixing fresh dev if it's the first time you're going to replenish).

So 'tank mix' you use only the first time and then you keep revitalizing that same developer volume using replenisher.

Click to expand...

So how much replenisher do you add back into a 1L of fully used developer? Again sorry this confuses the hell outta me, and is it the replenisher concentrate? Or just the raw replenisher that’s not diluted? So confusing. Sorry again

legstowalkmyself said:

So how much replenisher do you add back into a 1L of fully used developer?

Click to expand...

Like I said, read the manufacturer's instructions. it should be in there somewhere. They usually cite it on a square meter basis. E.g. for the Fuji developer I use it's 90ml per square meter of paper processed.

legstowalkmyself said:

is it the replenisher concentrate?

Click to expand...

It's the concentrate with water added to make the replenisher as it says on the bottle, but NOT the 'tank mix' recipe. Usually the mixing ratio is somewhere in the neighborhood of 1 part concentrate to 4 parts of water, or thereabouts. Again, check bottle.

koraks said:

Like I said, read the manufacturer's instructions. it should be in there somewhere. They usually cite it on a square meter basis. E.g. for the Fuji developer I use it's 90ml per square meter of paper processed.


It's the concentrate with water added to make the replenisher as it says on the bottle, but NOT the 'tank mix' recipe. Usually the mixing ratio is somewhere in the neighborhood of 1 part concentrate to 4 parts of water, or thereabouts. Again, check bottle.

Click to expand...

“Replenishment rate of 160mls/m2 at 35C (15mls/ft2 @ 95F)”

I found this, I’m printing at 95F and use 60ml on 8x10 paper

Ok so this is what I’m going to do, I use 60mL per 8x10 so

600ml of used developer which is 10 8x10 sheets

10 X 15(replenishment rate)

150mL of replenisher added to a 600mL bottle of used developer?

legstowalkmyself said:

“Replenishment rate of 160mls/m2 at 35C (15mls/ft2 @ 95F)”

I found this, I’m printing at 95F and use 60ml on 8x10 paper

Click to expand...

One 8"x10" sheet = 80 square inches = 0.0516128 square meters.
So if the rate is 160mls/meter, the rate per 8x10 is calculated as follows:
0.0516128 x 160ml = ~8.25 ml per 8x10
So speaking practically, after every four 8x10 prints you need to take out some used developer, and add ~33 mls of mixed to specification replenisher - I'd use 35 mls.
When I'm replenishing, I prefer to add the 35 mls to the empty container, pour the used developer on top until the volume reaches the target maximum volume, and discard any small excess that remains. Otherwise, any volume loss due to carryover isn't properly allowed for.
If that is impractical:
- take out some of the used developer - say 100 mls - and put it to one side;
- add the 35ml of mixed to specification replenisher to the main volume of the used developer;
- pour from the 100 mls of the set aside used developer into the main volume of the used developer until the main volume of the used developer is full;
- discard the small amount of used developer left.
- make sure the main volume is well mixed.

MattKing said:

One 8"x10" sheet = 80 square inches = 0.0516128 square meters.
So if the rate is 160mls/meter, the rate per 8x10 is calculated as follows:
0.0516128 x 160ml = ~8.25 ml per 8x10
So speaking practically, after every four 8x10 prints you need to take out some used developer, and add ~33 mls of mixed to specification replenisher - I'd use 35 mls.
When I'm replenishing, I prefer to add the 35 mls to the empty container, pour the used developer on top until the volume reaches the target maximum volume, and discard any small excess that remains. Otherwise, any volume loss due to carryover isn't properly allowed for.
If that is impractical:
- take out some of the used developer - say 100 mls - and put it to one side;
- add the 35ml of mixed to specification replenisher to the main volume of the used developer;
- pour from the 100 mls of the set aside used developer into the main volume of the used developer until the main volume of the used developer is full;
- discard the small amount of used developer left.
- make sure the main volume is well mixed.

Click to expand...

What do you mean by take out some used developer? Like assuming I have a bottle of used developing I’m emptying into after every print? And if so

Bottle of used developer from four 8x10 prints

Pour 35ml of replenisher into empty bottle

Pour the used developer from the used four 8x10 prints on top of the replenisher in bottle

I’m confused by the “target maximum”, how would there be more left over? Sorry maybe I should just skip out on doing this lol

I would use Matt’s suggestion of using a 1 liter bottle of developer.
Use it for 4 sheets. Before you pour the used developer for the 4th sheet back into the 1 liter container, pour in 35 ml of fresh replenisher, then top off with the used developer from sheet #4, discarding any excess.
I use this method on a roller transport machine and it works perfectly (though the quantities are different).
It’s not hard once you get the hang of it!
Good luck

legstowalkmyself said:

What do you mean by take out some used developer? Like assuming I have a bottle of used developing I’m emptying into after every print? And if so

Bottle of used developer from four 8x10 prints

Pour 35ml of replenisher into empty bottle

Pour the used developer from the used four 8x10 prints on top of the replenisher in bottle

I’m confused by the “target maximum”, how would there be more left over? Sorry maybe I should just skip out on doing this lol

Click to expand...

You start out with a working solution bottle of seasoned developer. Initially, that seasoning came from the addition of the starter to the original mix version of the developer. As you use and then replenish the contents of that bottle, the seasoning is maintained by:
1) partially using up the developer over time, by regularly developing prints in it, which adds byproducts;
2) discarding some of the used developer regularly, which removes some of the byproducts; and
3) replenishing the developer regularly, by adding replenisher.
Say you are using a 1 litre bottle, as suggested. That bottle contains your working solution.
And that 1 litre is your "target maximum".
Each time you process a run, you pour the used developer back into that bottle.
After 4 runs, before you pour the used developer back in to the working solution bottle, you add to the bottle the 35 mls of replenisher.
Then you pour the used developer back into the working solution bottle, but you stop when the volume reaches the 1 litre mark - your "target maximum".
Anything left over in the container of used developer - which should be something close to 35 mls, but probably a bit less, due to loss from carryover - that left over used developer should be discarded.

legstowalkmyself said:

Sorry this kinda stuff confuses the hell outta me

Click to expand...

Use it one-shot then and don't go down the replenishment maze. Throw it out afterwards. Doing color and trying to be a cheapskate like me at the same time leaves you wide open for WAY more waste in supply costs than trying to recycle used chemistry.

legstowalkmyself said:

What do you mean by take out some used developer?

Click to expand...

The idea of replenishment is that you replace some of the used developer with fresh replenisher. That way you keep the activity level of the volume of developer you use the same, regardless of how many prints processed. To accomplish this, you need to take into account:
* How much developer was lost in the process (sticking to the paper and the drum)
* How much work the developer has had to perform (how many prints processed)
* How much replenisher is needed to compensate for the amount of work performed (manufacturer's specification)

I've made you an infographic that walks you through the process:


To explain:

1: you start with two mixes, your working strength developer mixed according to the 'tank mix' formula on the bottle, which includes starter and extra water. And also a volume of replenisher that does not include the starter; it's just replenisher concentrate + the right amount of water.

2: Then you merrily process prints, every time you process a print you take the amount of developer you need from the working strength bottle (e.g.60ml) and after the development run you put it back into that bottle/jog. As you proceed, you will lose a little developer as some will hang on to the print and the drum ('attrition'). The developer will also alter its characteristics, because it's gradually getting more and more used. If you work with a 1000ml volume of working strength developer, you can easily process 20 or so prints before going to step 3 (replenishment). Mark the number of prints you've done.

3: To replenish, you essentially replace some of the used developer with fresh replenisher. How much you need to replenish depends on how much paper you have processed. Multiply the number of prints by the surface area of one print, then multiply that square-meter number with the replenishment rate (e.g. 160ml/m2) indicated by the manufacturer. Let's say this ends up being a 80ml volume (ca. 10 pcs 8x10" prints). Measure 80ml of replenisher into a cup. The idea is that you will always have the same amount of working strength developer, so if you're going to replenish with 80ml of replenisher, you need to discard some of the used developer. Since you've already lost a little of your used developer due to attrition, you should eyeball how much developer you've left and only discard the difference. For instance, if after processing 10 prints you end up having lost around 60ml of the original developer, you now only have 940ml used developer. If you were to add the 80ml of fresh replenisher to this, you'd end up with 1020ml, but the target was 1000ml. So you need to discard 20ml of the spent developer. Do this first, and then add the 80ml of fresh replenisher. You are now left with 1000ml of developer that is brought back to a 'like new' activity level.

After replenishment, you can go back to your merry printmaking. So you go back from step 3 to step 2, and NOT to step 1 unless for some reason you destroyed your developer (e.g. contaminated). You can save your working strength developer batch between sessions in a PET bottle with no air on top. Some people like wine bladders; those work too. The developer generally keeps just fine for weeks or months. You can store the diluted replenisher in the same way.

The process of replenishment may seem delicate with all the exact volumes being thrown around. In practice, it's pretty robust and you can eyeball your way through it without any harm. Just like Matt, I personally lean towards slight over-replenishment, so I often round up the amount of replenisher I use (if the calculus says I need 80ml, I will generally go with 100ml).

I hope this illustrates the process and removes some confusion. As I indicated before, in practice it's a lot easier than how it may look if you just start out.

F4U said:

Use it one-shot then and don't go down the replenishment maze.

Click to expand...

That's possible, but wasteful. A replenished system is also not necessarily any less consistent, but it definitely is more work and as witnessed here can be confusing at the start, although the principle is really very simple. Overall if someone says "I like to do A" the constructive approach is to help them do A instead of "forget about it, don't do A". OP knows how to print color without replenishment. He now wants to move on to a more economic and efficient process. Kudos to him; let's try and help him.

legstowalkmyself said:

Sorry this kinda stuff confuses the hell outta me

Click to expand...

Hi, in my view these things are hard to understand unless you can kinda grasp the principles behind them. The manufacturer's instructions generally give step-by-step instructions; they pretty much have to do it this way. But it doesn't help one understand the "whys" behind everything.

Let me try to explain the principles; this is gonna get kinda wordy. But if you can follow things you will hopefully get a grasp of whats going on.

I was first exposed to these concepts as a young photolab QC tech in the 1970s. One of our duties was to refill processing machines after overhauls been completed. Although I had quite a lot (I thought) of photo experience by then it was still confusing. The senior tech explained it to me thusly: he said, Don't think of it as "developer." Think of it as either "tank solution" or "replenisher." Where the so-called "tank solution," or as koraks said, "tank mix," is what most photographers would refer to as simply "developer." (In photo labs we use the term "tank" in reference to processing machine tanks, thus the so-called tank solution. )

Here's how it sorta works. The developer "tank solution," aka just "developer" to non-lab people, is where the film or paper is actually developed. During development two main things happen to the developer. First is that a certain amount of developing agent is "used up," depending on the extent of "developing" that has to be done. (Unexposed film frames, for example, will not exhaust the developer as no silver is developed. Whereas completely light-fogged film will exhaust the developer much more strongly than "normal" exposures.) The second thing happening to the developer is that development byproducts are being released into it. Typically these byproducts will slow down the development significantly. But... in the specific case of RA-4 paper, this effect is fairly minor.

So... the way that this developer exhaustion is traditionally dealt with in the photo processing business is through the use of so-called replenishers. Such replenishers are (ideally) formulated to exactly counteract the bad effects of developer exhaustion. The developer replenisher does mainly two things. First, it restores the tank-solution developing-agent concentration back to the original aim specification. (To do this replenisher must be overly concentrated with respect to the actual developing-agent.) Second, the replenisher volume must be high enough to dilute the unwanted byproducts back to the original aim specification.

As a note, the manufacturers typically offer developer replenishers designed for different replenishment rates. If you compare high-rate vs low-rate replenishers, the low-rate replenisher will necessarily a higher concentration of the developing agent. At the same time the low-rate replenisher will contain a lower concentration (perhaps zero) of "byproducts." But in either case the replenisher will be significantly "stronger," in developing action, than the standard "tank solution," so the replenisher is not suitable, as is, for use in developing film or paper.

Now for the topic of "starter solutions." You might wonder, what is the point of these? Well, in the photo processing business labs typically do not expect to have to refill their processing machines on any regular basis - a commercial replenished system can run indefinitely. Certainly for years and years, using machines with filtered circulation systems and being "monitored" by qualified technicians who can adjust the replenishment rates as needed. So the typical photo lab will only purchase and stock replenisher packages.

But occasionally they will screw up and have to fill a processing machine with freshly mixed "developer" (tank solution.) So the question is, how can they do this when all they have are replenisher mixes? Well, the manufacturers have accommodated this by also manufacturing the so called starter solutions along with specific instructions for their replenishers. In essence these allow photo labs to convert developer "replenisher" into developer "tank solution." In essence this conversion does two things. First, since the replenisher has an extra-high concentration of the developing-agent it needs to be somewhat diluted with water. And this will vary with the design replenishment-rate of the specific replenisher so one has to follow the instructions specific to their replenisher. The second thing is that the replenisher is at least somewhat deficient in "development byproducts," so these are supplied in the starter solution. (As I mentioned before, in the specific case of the RA-4 process, it is not very sensitive to said byproducts, so not as important as, for example, as in the C-41 film process. ) The starter solution can contain some other things, but the main things are as mentioned above.

A couple of notes related to replenished systems in general. When you see published replenishment rates these are based on an "average" amount of exposure. Ideally you would have a way to keep track of the developer's "activity" and make periodic adjustments to the replenishment rate as needed. But... RA-4 is especially forgiving in this respect, so... ? But if you were to make a lot of prints with nearly black backgrounds, this might require something like 3 to 4 times the "normal" replenishment rate. So just something to be aware of.

Second note: color developers, in general, have pretty small amounts of "preservatives" compared to typical b&w developers. (The preservatives help protect the developing-agent from oxidation.) So if your processing method aerates the developer to a significant degree it might not be suitable for a replenished system. My color experience is all in commercial-type systems; I don't have much idea how far one can push things when aeration becomes significant. I would defer to the actual experience of others here.

Consider also that replenishment in color chemistry is meant for continuously working machines, so continuously replenished tank solutions. With home processing it is not the usual case, solutions may sit for days, or even weeks without use (I would not try replenishment in the case of months). So keep the solutions absolutely air tight to reduce the effect of aerial oxidation in the equation, otherwise the replenishment rate is going to be complicated.

halfaman said:

I would not try replenishment in the case of months

Click to expand...

It works surprisingly well. I've frequently picked color printing back up after a hiatus of a couple of months only to find everything worked as well as the day I stopped printing. No guarantees along these lines, but just to illustrate that the process is often more robust than people imagine.

legstowalkmyself said:

What do you mean by take out some used developer? Like assuming I have a bottle of used developing I’m emptying into after every print? And if so

Bottle of used developer from four 8x10 prints

Pour 35ml of replenisher into empty bottle

Pour the used developer from the used four 8x10 prints on top of the replenisher in bottle

I’m confused by the “target maximum”, how would there be more left over? Sorry maybe I should just skip out on doing this lol

Click to expand...

What you've described is correct so you aren't confused after all, as long as you end up with the same volume of developer+replenisher as you had developer only when you started. You just don't pour that last 33 ml of used developer back into the bottle. Assuming it was completely full when you started, or you have it marked at the original level, that will be simple because there won't be room for it.