Kodak RA/RT Usage Advice (Replenishment)

I think I had one with my M305. It just worked, never had any problems with it. It's a plain transformer, no voltage regulation. Go ahead and buy it if you want a collection of transformers, but I don't think it'll help much to hop from one transformer to another (of virtually identical operation).

koraks said:

I think I had one with my M305. It just worked, never had any problems with it. It's a plain transformer, no voltage regulation. Go ahead and buy it if you want a collection of transformers, but I don't think it'll help much to hop from one transformer to another (of virtually identical operation).

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Hey Koraks. I think you're thinking of the TRA transformer for Durst enlargers. The one I've found is the EST which is actually a stabilized version of this transformer. They look identical but are different inside

Yeah you're right, I had a TRA.
In the photo I see not signs of any stabilizing circuitry. You could ask the seller to snap some more pics of the inside to be sure. But it's possible someone stripped the part out that you're actually looking for.

Bumba said:

Hi, I've searched high and low to get as much information on this kit as possible but I've got some questions left.

I know many of you use it as a room temperature developer. I'm planning on using it in drums but I'm in the UK so the kit costs a fair bit (think it's probably cheaper in America). It's costing £120 for both the dev and blix 20l kits. I would like to use it as a replenished system if possible. I searched through the Kodak documents and got roughly a value of 14ml per 10x12 (10ml per 8x10) but this seems a bit low to me. I was thinking more along the lines of 40ml which is 1/3 of what my drum requires. Does anyone have any advice for a replenishment system?

Also are these chemicals best used at room temp or higher temp. I'd prefer to use it at room temp but it's not much issue heating them up if it increases the image quality.

Thanks for any help
Bumba

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Kodak RA4 developer is recommended to be used at 35c and develop each piece of paper for 45 seconds. I have never seen any times/temps for any other than 35c. If you extend the developing time because of a lower temperature then if you have to make multiple test strip prints to get the colour balance/exposure correct then trust me you will soon get bored!

The recommended replenish rate in a NOVA is 10cc per 80 sq ins (i.e. one sheet of 10x8. I do this for the stop bath and the blix at the same rate. I don't know what equipment you are using but for a 12x16 NOVA you use 2 litres of dev, & stop and blix to start out with. With the reamaining18ltrs of working solution you could successfully develop 1800 sheets of 10x8 paper - that is 18 boxes. I don't know of any other chemical that is as economical as this.

Work out how much a box of 100 10x8 costs then multiply it by 18 and you will realise how cheap it actually is. You can cut the cost even more by buying the paper by the roll. I buy Kodak Endura in an 80m roll of 12 wide this works out when compared to 12x16 boxes is about 14 of the price. You have to make a light tight dispenser to hold the roll but it isn't difficult or expensive with aluminium sheet using riveted corner strips to hold it together.

I have just checked and 18 boxes of 10x8 Fuji paper would cost you £648.00 Kodak is not available in boxes but my last 80m roll of Kodak Endura bought 6 weeks ago cost £109.00

koraks said:

Yeah you're right, I had a TRA.
In the photo I see not signs of any stabilizing circuitry. You could ask the seller to snap some more pics of the inside to be sure. But it's possible someone stripped the part out that you're actually looking for.

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Unfortunately it's one I've already purchased thinking it was a stabilizer. There wasn't much information about it as it's an older bit of equipment. I found a photo of the internals of the EST stabilized transformer. I suppose the tower on the right is the stabilizing part of it. From what I've read the yellow capacitor on the right is prone to blowing so not sure if I'm prepared to take on the risk of having to replace it in such event. Could be an easy job though.

BMbikerider said:

Kodak RA4 developer is recommended to be used at 35c and develop each piece of paper for 45 seconds. I have never seen any times/temps for any other than 35c.

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Search Photo Engineer's posts for room temperature developing of RA4 paper - he does it routinely, and I trust him completely on matters of this nature.

There's a J-39 publication on Kodak Alaris website listing time and temperature for trays and drums.
Here's a link.

https://imaging.kodakalaris.com/photographers-photo-printing/resources/chem-tech-info

mshchem said:

There's a J-39 publication on Kodak Alaris website listing time and temperature for trays and drums.
Here's a link.

https://imaging.kodakalaris.com/photographers-photo-printing/resources/chem-tech-info

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It is titled: "Tray, Drum, and Rotary-Tube Processing with KODAK EKTACOLOR RA Chemicals"

Btw I'm getting really nice results processing for 2 min + plus drain time @ 20°c in drums. No prewet and it meets my high standards (I'm a perfectionist). This is for Kodak RA RT with no starter added.

Bumba said:

Btw I'm getting really nice results processing for 2 min + plus drain time @ 20°c in drums. No prewet and it meets my high standards (I'm a perfectionist). This is for Kodak RA RT with no starter added.

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Perfect!

My working solution has bin sat around for a little bit and the colour has shifted towards cyan but I'm still getting good blacks. Are my chemicals still good and can I just compensate with the filtration?

If the black's are good and the white's are not stained then I would just compensate. But of course it may not simply be the paper developer, Manufacturers of film appear to sometimes change the colour of the film base which will also shift colour balance and even development times will do the same either darker or lighter or if it is not fully bleached/fixed will do the same. I have even had two identical.films (Fuji Superia 400) developed in the same tank and the same time were both slightly different - go work that out!

BMbikerider said:

If the black's are good and the white's are not stained then I would just compensate. But of course it may not simply be the paper developer, Manufacturers of film appear to sometimes change the colour of the film base which will also shift colour balance and even development times will do the same either darker or lighter or if it is not fully bleached/fixed will do the same. I have even had two identical.films (Fuji Superia 400) developed in the same tank and the same time were both slightly different - go work that out!

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Haha they like to keep people on their toes I guess. I think my chemicals are just turning slightly bad. I'm trying to run a replenished system with drums so I guess the oxidation is starting to creep in.

I currently replenish at the rate Kodak recommends 10ml per 8x10 but the time for a full turn over of chemicals is over two months so I guess it's allowing for oxidation. I read somewhere that for drums it's good to replenish at 3x the recommended rate so I'll try that with new chemicals. That would bring the turn around to just under a month with my usage.

If anyone know more about it then please tell me of I'm on the right track as I'm winging it a little.

Get a pH meter and verify if your developer pH remains correct. I think it's likely you're under-replenishing.

koraks said:

Get a pH meter and verify if your developer pH remains correct. I think it's likely you're under-replenishing.

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Why look for a problem when there isn't one! If it were under replenished then the colours would be less saturated not have a colour imbalance. Let me spell it out once again "The recommended replenishment rate for Kodak RA4 is 10cc per 80sq ins of paper. No if's or but's.

What you do risk with drum processing however is cross contamination which happens when the drum is not rinsed out completely after each print and a small amount of even diluted blix will affect the colour. Initially I was not aware that a drum was being used. For me a drum processing method is a no brainer. Longer, tedious and with the risk of cross contamination. As far as I am aware there is no given rate for replen in a drum processing system. If it were efficient then commercial processing houses would use more of them. Their method is a long continuous chain...….developer...…... possibly stop...…...bilx and finally stabiliser/wash with auto replenishment at 10cc per 80 sq ins.

The amateur version of the commercial system is the Nova processor or similar so cross contamination cannot occur.

I have just done a search on the web and there are two possible reasons for a cyan cast (Apart from inaccurate filtration) These are developing at a lower temperature than recommended (Less than 25C is mentioned) or as I suggested cross contamination with blix.

Bear in mind when you rinse out the drum (if you do) you must fully dry the drum which is not easy either. The drum will probably be cooler than the chemicals so after placing the paper inside putting it in the processor or whatever you use and then pouring in the chemicals there is a good chance that the developer will be cooler than you wish for. With the colour layers each is designed to develop at an identical rate however, with any deviation either lower or in some case over the development will be uneven with one rate developing quicker than the other. At a rough guess this is where the cyan cast is coming from.

This will not happen in the white unexposed rebates because there has been no light to affect the layers.

BMbikerider said:

Why look for a problem when there isn't one! If it were under replenished then the colours would be less saturated not have a colour imbalance. Let me spell it out once again "The recommended replenishment rate for Kodak RA4 is 10cc per 80sq ins of paper. No if's or but's.

What you do risk with drum processing however is cross contamination which happens when the drum is not rinsed out completely after each print and a small amount of even diluted blix will affect the colour. Initially I was not aware that a drum was being used. For me a drum processing method is a no brainer. Longer, tedious and with the risk of cross contamination. As far as I am aware there is no given rate for replen in a drum processing system. If it were efficient then commercial processing houses would use more of them. Their method is a long continuous chain...….developer...…... possibly stop...…...bilx and finally stabiliser/wash with auto replenishment at 10cc per 80 sq ins.

The amateur version of the commercial system is the Nova processor or similar so cross contamination cannot occur.

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Of course, a RT processor is very nice and indeed the small-scale equivalent of a lab setup. However, not all of us have the option to use one, for several valid reasons. In those cases, tray or rotary tank development are valid options, but they do come with a caveat. That caveat is that the replenishment rates as listed by e.g. Kodak and Fuji may not be sufficient. The reasons for this are (1) larger air-fluid interface in a tank or tray system and (2) lower processing volumes, making for substantially longer tank turnaround times than the chemistry manufacturer assumes. The result of this is higher oxidation rates and pH drift. I do not base this in theorizing, but on observation and measurement in my darkroom over a period of multiple years. So there are if's and but's, I'm afraid.

Through experimentation I found that a reliable way to work with low developer volumes in a tray setup at low temperatures (room temperature; i.e. significantly below 25C, depending on the season) with excellent print-to-print consistency can be achieved when replenishment is based on pH monitoring instead of processed paper surface. The paper surface approach works fine of course, but only if the conditions of limited oxidation and sufficiently high tank turnover are met. As I pointed out, this is often not the case in a home darkroom. In my experience, if the developer pH is kept constant by replenishing to such an extent that target pH is maintained, the prints are consistent and of high quality - even with irregular printing sessions (with pauses of several weeks between sessions), processing at lower temperatures (in the range of 15-25C) and long print session times in which the developer sits idle in the tray for many hours. Replenishment rates are on average significantly higher in this scenario than outlined by the manufacturer - even if low-volume chemistry is used.

Of course, it's still correct that cross-contamination can (literally) spoil the broth, although this is more of a concern with rotary tanks than with multiple tray processing, and even then is easily managed by thoroughly cleaning the tanks between prints (which I find an annoying hassle, hence my preference for trays). Also, lower temperatures than RA4 spec will be a problem if development time (and to a lesser extent, blix time) is not adjusted for this. With proper adjustment (which can be experimentally determined), I find it is not a problem.

So I appreciate your pointers to aid other workers, but please allow for some nuance to your information based on the experience of others, as your remarks insufficiently account for the process conditions to which manufacturer-indicated replenishment rates are subject.

Bumba said:

Haha they like to keep people on their toes I guess. I think my chemicals are just turning slightly bad. I'm trying to run a replenished system with drums so I guess the oxidation is starting to creep in.

I currently replenish at the rate Kodak recommends 10ml per 8x10 but the time for a full turn over of chemicals is over two months so I guess it's allowing for oxidation. I read somewhere that for drums it's good to replenish at 3x the recommended rate so I'll try that with new chemicals. That would bring the turn around to just under a month with my usage.

If anyone know more about it then please tell me of I'm on the right track as I'm winging it a little.

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With correct replenishment the life of RA4 developer can be extended - apparently almost indefinitely! I have used the Kodak and the Tetenal RA4 and in a Nova processor I have only drained it out after 13 months simply because of the build up of tar and sludge. Once cleaned I made a whole new batch and continued as before for many months. If you are using a drum, I would whole heartedly recommend a Nova. New, they are vey expensive but readily available used on E bay or via www.secondhanddarkroom.co.uk for a lot less than new. I would never use a drum because of the inherent problems and a Nova takes up much less space to work.

Same here; I've been working with 500ml developer for about 2 years now, replenished. It just lastst and lasts. I only filter it once in a blue moon if there's too much sludge to my liking.

I use trays but if an attractive RT processor comes along, I'd certainly give it a shot. Haven't been looking very actively though.

Right everyone. Everything was going smoothly and I was feeling confident then this happened. Made these three test strips in a row and got this big red mess thrown out at me. Changed the filtration by 1m and that was it.

I'm not sure if it's a chemical problem because I started using a slower agitation but I doubt that would be the cause of it because it's still constant agitation. I was considering blix staining but I've got white boarders. Maybe developer went a bit wonky but wouldn't make sense due to the two previous ones looking good.

Possibly a problem on the enlarger side of things. I'm thinking either bulb (but it's a new bulb) or something to do with the device that reads the voltage off that I have in between the mains and the enlarger. Doesn't make sense as the density is good.

Long shot but could it be the paper also? It's all from the same box of Fuji Crystal Archive

Did you flip the filters out of the way when focusing or something? This is what you get with no filtration. On a durst it's the lever on the side of the head.

koraks said:

Did you flip the filters out of the way when focusing or something? This is what you get with no filtration. On a durst it's the lever on the side of the head.

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Just checked and the filters were still in place. I never really flip them out the way. I'm truly baffled by this one

Update - I noticed that the display on the device that gives a voltage display fades over time. I just thought it was because it was cheap but I found out that it only fades when the enlarger is turned on.

I think that's the cause somehow so I'll try putting it on a different circuit and see if that helps

I'm back and have had limited success. Anyway, I changed my bulb holder and that made a massive difference and helped with a bunch of problems I was experiencing. My new bulb was used in my old holder and the ceramic has browned off and the ceramic is also very thin and missing on one edge and the terminals have gone black inside. Im not sure if this is giving me problems too. Is this blackening normal on bulbs. It's fairly new.

I've also flipped my bulb round and the colour went really green which doesn't seem good.

Thanks

Hi everyone, I'm back. Hope everyone is doing well btw.

The Kodak docs give data for up to 27°c but I've found 25°c to be best for ease with my set up because the temperature is a bit more stable over a session.

I've found that if I develop for longer than suggested it starts to develop a bit of a yellow cast. I tried this at room temperature and I couldn't settle on a good development time. Also if I developed for 3:00 at 25°c instead of 2:20 then it happened.

Is there a correct amount of development or doesn't it really matter as long as you're consistent? I'm just considering the longevity of prints. The developer develops a test strip exposed to room light to full black at 8-10s @ 35°c and 15s @ 27°c.

Also is there anything to beware of if I'm straying from the published Kodak times. I'm going for 2:20 @ 25°c but half of me feels like I should stick to the times Kodak published.

Thanks all