Ra4 processing consistency advice

Bumba · Jul 25, 2019

Hi everyone, I'm basically having trouble getting consistent results with my processing. I'm sure it's the processing causing problems as I have done test strips at the same filter values and they come out looking different. The difference is in the red filtration on my test strips.

I am using Jobo drums and hand rolling them. I have tried at a few different times and temps but the problem hasn't been solved. My process is probably over complicated but here it is:

Chemicals @ 31.5c (so they drop to 31 after I pour them in)
Water bath that heats the chemicals and is also used as a water jacket for the drum @ 32c (so it comes to around 31 when I use the dev).

Pre-warm - 1 min
1st pre wet - 30 secs
2nd pre wet - 30 secs
Dev - 1:05 with 20 sec pour
Stop bath - 20 secs
Wash - 20 secs
Blix - 1:05 with 20 sec pour
Final wash - 3x 30 secs

Am I over complicating things and am I leaving too many opertunities for temp drift? I don't use a heater and instead just use boiled water to bring everything to temp. I also use the same volume of water in the bath each time.

Tl:dr - having problems with consistent print colours as the red is shifting around between each test. Processing using a Jobo drum by hand with no heater.

Sorry for the long and confusing post. Any help would be much appreciated. Also due to space I think owning a Jobo might be out of the question and also would like to avoid aquarium heaters as I dont have a socket near to my processing area.

Thanks

Photo Engineer · Jul 25, 2019

How much fluctuation in CC value? 0.1, 0.2, 0.05 etc. Can you estimate or show examples?

Your process looks fine, but I would give a little more wash.

PE

Bumba · Jul 25, 2019

Thanks for the quick response. I just had another look and the problem looks to be domsometh else. I'll delete this thread and start a different one when I figure out what's going on

KN4SMF · Jul 26, 2019

You can't delete threads on here, so you might as well use the same one. Color is tough. It's not something you can do once in a while. Your process has to be repeatable, as in every day. Otherwise it's hit and miss always. I highly suspect you are having temperature problems, chemistry age changes, and lastly paper changes, in that order. Nothing has any stability at all. I was an offset printer for 38 years. Everything can go to heck in a handbasket from one day to the next. Indeed from one job to the next in the 8 hour work day. Even in the same 3000 sheet run. It's a tightrope walk the whole time. My customers were paying for 3000 or however many sheets was on the job jacket, that all had to look the same--to HIM. But to me, I could leaf through the finished job hoping to see the good one somewhere in the stack.

BMbikerider · Jul 26, 2019

I found in the very dim and distant past that processing RA4 in a drum is setting you on a hiding for nothing. Having to wash out the drum between each print and then drying it is a task that is fraught with problems if the last remnants of the blix is not cleaned out. I have been printing RA4 since 1991 and soon dumped the roller system for a deep tank processor. That is the 1st step to getting consistency.

Then the temperatures you are using are too low. The recommended temp for Kodak and Tetenal RA4 is 35c and the development time 45 seconds. Whilst altering the times as you have may compensate for the lower temperatures, it is not what they were formulated for and there could be your problem.

With a deep-tank such as a NOVA you do not have to pre wash and the possibility of cross contamination virtually eliminated. Yes I still make mistakes, but that is always down to operator error and not the equipment or the processing sequence

Ian C · Jul 26, 2019

Is the power supply of your enlarger of the voltage-stabilized type, or are you using a line stabilizer on the AC power to the enlarger? If not, then voltage fluctuations in the supply current from one exposure to another can cause frustrating color shifts from print to print. Too, the conductors of the lamp, socket, or both can become corroded and lead to such problems even if the supply voltage is stable.

John51 · Jul 27, 2019

BMbikerider said:
I found in the very dim and distant past that processing RA4 in a drum is setting you on a hiding for nothing. Having to wash out the drum between each print and then drying it is a task that is fraught with problems if the last remnants of the blix is not cleaned out. I have been printing RA4 since 1991 and soon dumped the roller system for a deep tank processor. That is the 1st step to getting consistency.

I've got a Nova slot processor that I haven't used yet and sometimes put a print on a clip and go through the motions with my eyes closed. Not that easy for me to get paper into the slot.

How do you time the 45 seconds?

Then the temperatures you are using are too low. The recommended temp for Kodak and Tetenal RA4 is 35c and the development time 45 seconds. Whilst altering the times as you have may compensate for the lower temperatures, it is not what they were formulated for and there could be your problem.

With a deep-tank such as a NOVA you do not have to pre wash and the possibility of cross contamination virtually eliminated. Yes I still make mistakes, but that is always down to operator error and not the equipment or the processing sequence

John51 · Jul 27, 2019

I somehow managed to get my post embedded in the quote.

I've got a Nova slot processor that I haven't used yet and sometimes put a print on a clip and go through the motions with my eyes closed. Not that easy for me to get paper into the slot.

How do you time the 45 seconds?

BMbikerider · Jul 27, 2019

I use a simple count down electronic timer easily and cheaply bought from a shop that sells cookery equipment. Mine cost about £5 and I have had it for years I set 45 seconds on the display and press the button and the electronics do the rest, with a beeping sound after the time is up

pentaxuser · Jul 27, 2019

Colour printing can be frustrating unfortunately. So the test strips done in the same chemicals, for the same time and same filtration as the prints come out looking red? What do the prints look like, any colour cast there? It would appear that something different happens with the test strip? If the chemicals are the same then it suggests that the strips are subject to something that the prints aren't. Ian C's suggestion about voltage stabilisation or lack of it might be close to the cause

I'd look at changes other than those connected to the developing process as at face value this seems to be the more fruitful avenue of investigation

I might help if you show us a scan of the test strip and then one of the prints with that section on it.

pentaxuser

koraks · Jul 27, 2019

Replenished developer or one shot?

DREW WILEY · Jul 27, 2019

I get extremely good repeatability with drums. Fresh chemistry is important. I mix just enough at a time for a single day's work session. I use drums that fill and drain quickly (everything from 8x10 up to 30x40 inch). I standardize on 2 min Dev and Blix @ 30C (including a 10sec drain - 20 sec is WAY too long). It's hard to be consistent at short temps, especially with a slow fill and drain drum like Jobo. Prewet and stop can be shorter (I use 1 min). Hand rolling is fine unless the surface is cold. If you need better temp consistency inside the drum, wrap it with some good quality closed-cell rubber foam insulation. I always use chem one-shot. If I wanted to do replenishment, I'd set up the Thermaphot roller-transport machine that I have in storage; but I doubt I'd get as consistent results. It's extremely easy to get all chem residue out of drums; just rinse them out right after each use! But I do add a brief plain water rinse between the stop and Blix steps. I also do a final in-drum wash using at least five changes of water, being conscious of sloshing the inside bottom of the drum too - that automatically gets out all residue.

halfaman · Jul 28, 2019

I had a problem years ago but with magenta, it was related with the bulb. I used a long life type for home lightning and the magenta shift ocurred when it was aproaching the filament failure. Now I only use bulbs for projection that are much more stable.

pentaxuser · Jul 28, 2019

In my early RA4 printing days I noticed that my test strips had reddish/magenta areas occasionally on the side of the test strips but full prints were fine. It eventually struck me that I had used some reflective tape that produced a glow on my paper trimming easel. I had used the tape to guide my cutting of a 8x10 sheet into 4 pieces of 4x5. If I moved the sheet into position from the opposite side from the tape then I was usually fine but if I lifted the sheet into position over the tape then it was a problem.

My tale may have nothing to do with the OP's problem but I use it as an example of how such things can be easily overlooked when looking for the "usual suspects"

pentaxuser

btaylor · Jul 29, 2019

I had a somewhat similar problem with yellow speed easels. Depending on the color and density of the negative I was printing I would sometimes get reflections from the ends of the easel causing odd color fogging. A bit of black tape took care of it.

Bumba · Aug 6, 2019

Oh wow, thanks for all the great help. Didn't expect so much advice and tbh I forgot I started this thread and kept working away in the darkroom to no avail. I shkush work smarter, not harder. Firstly I'll attach a picture of two test strips that were processed at the same time and temp with the same filter settings.

1) I think it's possibly more of a denaity problem than colour shift on closer inspection. Any shifts are normally 1 or 2 cc (Durst values).

2) No idea about power supply. It runs off UK mains and through a transformer box I think. Not very good with electronics haha.

3) Chemicals are reused and not replenished (don't crucify me please).

I'll try scan the test strips before the end of the day and post them as it's a bit difficult to see the difference. Most the time the difference isn't as extreme as this.

Bumba · Aug 6, 2019

These are the scanned test strips if they help.

pentaxuser · Aug 7, 2019

Well I certainly can't see any red cast here. Can you explain again what the difference is in the two scans in terms of what you did?

When I saw the overhead shot of this scene I kept on getting a feeling of deja vu that is I kept thinking I had seen these scans before but I may be completely wrong.

pentaxuser

Bumba · Aug 8, 2019

pentaxuser said:
Well I certainly can't see any red cast here. Can you explain again what the difference is in the two scans in terms of what you did?

When I saw the overhead shot of this scene I kept on getting a feeling of deja vu that is I kept thinking I had seen these scans before but I may be completely wrong.

pentaxuser

Hi Pentaxuser,
Both of these were exposed and processed exactly the same but there is a fair difference in them and I can't understand why. I thought it was a red cast at first but now I'm thinking the difference is in the density between the two.

Also I had another thread with a similar problem with the same begatine that I think you responded too but I solved that problem and another one reared its ugly head.

Photo Engineer · Aug 8, 2019

I think it is density, seeing the examples.

PE

pentaxuser · Aug 8, 2019

Bumba said:
Hi Pentaxuser,
Both of these were exposed and processed exactly the same but there is a fair difference in them and I can't understand why. now I'm thinking the difference is in the density between the two.

Thanks for the reply. Yes it does look like a density change but if it's the same neg, exposed and processed in exactly the same way and presumably processed one after the other, I wonder how this density change can occur?

I wonder if the light intensity has altered so that in effect the exposure isn't the same. This can happen with bulbs that are almost at the end of their life. Usually unless the exposure is very short you tend to see the intensity change as it rises then falls.

Long shot now: Is there any chance that the scanning could have changed between scans?

pentaxuser

Bumba · Aug 8, 2019

Okay so today I made a new test strip with fresh developer and the image had much better density than the other two. I was reusing my chemicals and I don't think I was developing the test strips for long enough meaning that some came out underdeveloped. I'll do some more tests and let you know what I come up with.

Does anyone have any tips on reusing chemicals with drum processing? I know I should use it one shot but it's 120ml per print so I'd be getting through chemicals too quickly.

P.s. I'm still getting good blacks with my reused chemistry which threw me off suspecting that was the cause.

Photo Engineer · Aug 8, 2019

Well, there you are. You say you know you should use it one shot, but you are re-using it. It is seasoning slightly after each use. And, if you use a prewet, it is being diluted just a bit as well.

The development time should probably be increased just a bit after each use, but with RA4, it is better to just overdevelop to start with and it will all even out.

To do this, try 1' 30" or longer, but not so as to give fog. This may clear up your problem completely.

PE

koraks · Aug 8, 2019

I reuse my ra4 developer as well, but:
I use trays, so the total volume is a bit bigger (usually 300-500ml) which dampens variations in activity a bit.
I replenish the developer as prescribed by the manufacturer.
I monitor the pH and adjust it when it gets out of bounds.
I do not use a prewet.
I develop for 1m30s at room temperature.
This gives me consistent results. I tried drums, but I found them too much of a hassle and prone to giving inconsistent results.

pentaxuser · Aug 8, 2019

Yes dumping 120ml per print will mean that you are going to get through a lot of developer. I used a Jobo processor and as I recall it, I had a stock of developer in a bottle in the heated water. This bottle contained I think 600ml . Each time after printing the 120ml of developer was returned to the 600 ml bottle which was shaken up and then another 120ml taken from it for the next print. The stock of 600ml was re-used but was replenished with fresh stock according to whatever the maker of the developer said was the replenishment rate . So if the replenishment rate was say 10ml per 35 sq ins of print ( 1 x 5x7) then after 5 prints I'd decant and dump 50ml from the bottle and add 50 ml of fresh developer to the bottle. In a heated Jobo processor the development time at 35C was I think 45 secs but not including pour time which in my drums was 2-3 secs only . Certainly emptying the drum of developer took nothing like 20 secs.

I note that at 31C you develop for 1 min 5 secs. If this a time from a table that gives temperature and time? You also mention a 20 secs pour so do you mean that you start pouring at 45 secs. 20 secs seems a long time to pour. As PE says you might want to develop for longer and if you start pouring at 45 secs at 31C this seems way too short.

However if this is the process you followed on every occasion it means that there was consistency each time so I am still puzzled about why the apparent change in density even if the dev time was too short in your process

Try developing for longer and see how this turns out

pentaxuser

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Ra4 processing consistency advice

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