using a stopbad with colour?

game · May 10, 2006

Hi everyone,
I have managed to get a proper colour print out of my machine this weekend. I'm thinking still about one thing though. My machine has a bath for develloper, then a unheated bath, then one for blix, then a few unheated ones for washing.
Right now I fill up bath1 with develloper, bath two with water, bath three with blix, and the rest again with water.
I was talking about this with a guy from school, and he pointed me on the fact that develloping does not stop when the paper is in bath2 filled with water. Seems he's right about that.
So develloping time is not right the way I do it, can be the only conclusion.
He said he uses a two bad system + washing in which the Blix bad is placed directly after the developper. Only with my machine that is unpossible since the second bath is unheated.
I use amaloco chemicals, and they have a stopbath chemical called S10 I believe. Should I use that?

If not what should I do? and also, what are the concequences of my current method(1.developper 2.water 3.blix)?

Hope to get these questions solved, with a little help from you guys.
THANKS - SAM

Nick Zentena · May 10, 2006

You can't use indicator stop bath. But any plain stop bath should work fine. I just use water and vinegar.

If you always do things the same way I wouldn't worry. You said you've gotten a good print without it? Why would you change?

Mick Fagan · May 10, 2006

I would think that the exit rollers from the developer bath would squeegee most of the developer from the paper, whilst the paper is in the cooler water bath, any developer is being diluted thereby lessening any on-developing.

Once in the bleach/fix bath, the paper is finally finished and then only has to go through the water wash bath at the end.

Does this machine (whatever it is) have a dryer at the end?

For many years I drum developed colour negative paper and used a stop bath after development. This was to ensure a controlled stop of the development, followed by bleach/fix in a not rushed time.

As your process will be identical, each and every time a piece of paper goes through, I cannot see that you will have a long term problem.

If you colour correct for the actual process you are using, then you will have a nice print.

If you maintain the bleach/fix bath correctly, then I see no real issue with longevity problems.

It seems that you have gotten yourself to a stage where you are happy with your colour prints, enjoy them and make many more.

There are so many ways of making a good colour print, you seem to have made another way.

Mick.

game · May 10, 2006

You are certainly right about that.
Only it is not really like I am at a certain stage yet. this weekend was my first time in a colour darkroom, and also the first colourprint I ever made. I just happened to be satisfied with it.
I might give Amaloco a call, and see in what cases the S10 stopbath is helpfull and if they'd recommend it.
thanks, it is good to know that my way is not wrong perse.
SAM

Photo Engineer · May 10, 2006

You cannot use a wash after the RA color developer, you must go into a stop of either 1 or 2% acetic acid.

Either that or you should go directly into the blix.

You can use indicator stop, but test it first as it can stain some papers.

PE

Mick Fagan · May 11, 2006

PE, just a question.

If one does a wash of a consistant type, as in through a R/T machine in the above scenario, would it matter that much from a longevity point of view, as opposed to a very strict quality controlled type of RA4 processing?

I ask this because a friend who has just bought an old B&W R/T machine has pretty much the same scenario as above.

I had mentioned using a stop bath but he was of the opinion that the squeegeeing effect of the exit rollers would virtually eliminate 99% of the excess developer with only the developer still in the emulsion(s) causing more developing.

From what I have seen and with our rudimentary testing, which was printing and developing in my R/T machine, then taking some exposed paper over to his darkroom to gauge the effectiveness and/or differences.

For what it's worth, there appeared to be almost no difference, except for a density difference that was just, and I mean just different, if you looked extremely hard.

Very interesting outcome, we thought.

Mick.

Photo Engineer · May 11, 2006

Mick;

Since color films and papers have multiple layers, when you wash, the development stops quickly in the top (cyan) layer, less quickly in the magenta, and can continue in the yellow for the entire wash time at 100 F. (I have personally tested this at EK and demostrated it. It was actually used in the EK drum process but had to be used with a special developer to prevent non-uniformity problems. (this order is specific to paper, the order is reversed for film)

So, the result with the RA developer is having a blue-yellow shift and nonuniformity as it does not contain the 2 special ingredients needed for an after development wash.

PE

Chan Tran · May 11, 2006

I always included a stop bath and a wash cycle between developer and bleach/fix steps. I do that for both Kodak RA-4 and Tetenal.

Photo Engineer · May 11, 2006

Chan Tran said:
I always included a stop bath and a wash cycle between developer and bleach/fix steps. I do that for both Kodak RA-4 and Tetenal.

A stop and wash will not hurt. It is just a plain wash that will hurt multilayer color materials.

PE

Ronald Moravec · May 12, 2006

I start to get stains in my 4 slot Nova, middle two being water only, after a few prints.

My conclusion is it works ok if you make a few prints and change water. It is easier to use the acid bath.

When I used to use drums, 4 water rinses were always fine, but that again was always fresh water.

chorleyjeff · May 13, 2006

I use Fuji Crystal Archive with no fix or wash between dev. and blix. I am sure I have read somewhere that this is what Fuji recommend. Anyhow it works well for me using a Nova 2 slot processor at 35c in Fotospeed or Paterson(RIP) chemicals, with another 2 slot processor for the print stabilisor/brightener.

Mick Fagan · May 13, 2006

PE, thanks for the reply.

Mick.

game · May 13, 2006

I emailed the manufacturer of my chemicals, amaloco, and this is what they said.

about dev time and temperature:

recommended ra4 time+temp is 45seconds @ 37degree celcius.
They say it is possible to get similar results with lower temperatures and longer times. temperatures above 39 celcius on the other hand could cause damp in the machine and below 32 could results in a colour desaturation, which I actually find quite interesting. Does anyone knows more about this?

About the water bath:
using a water bath is not wrong, but should be refreshed on a regular base, read after every 10 prints, because elsewhise the white in the prints will be off white and eventually even get a tint.
They recommended a S90 acid stopbath. Temperature should be raised 1 degree because development will stop directly.

So I think I will roder some S90 next time I'll be developping.

Thanks for the replys, and maybe someone can elaborate on the below 32 degree experiment.
- SAM

Stack8 · May 15, 2006

Stop bath

If the second tank could keep the bleach/fix 85 F, then skip the stop bath. The function of the bleach/fix is to stop the development action and couple the cyan dye layer (red), and removes unexposed silver.

game · May 15, 2006

I don't know what 85 farenheit means in celsius, but the bath has no from of heating, so I guess it's room temperature.
Sam

Photo Engineer · May 15, 2006

Stack8 said:
If the second tank could keep the bleach/fix 85 F, then skip the stop bath. The function of the bleach/fix is to stop the development action and couple the cyan dye layer (red), and removes unexposed silver.

Sorry, but the blix has no action whatsoever on producing cyan dye.

In fact, bad blix can have the opposite effect on some color papers and films and can change cyan dye back into the colorless leuco dye.

PE

Stack8 · May 16, 2006

The bleach in the bleach fix solution does in fact couple the cyan dye.

Photo Engineer · May 16, 2006

Stack8 said:
The bleach in the bleach fix solution does in fact couple the cyan dye.

Stack8;

I am sorry, but I helped design the blix for Kodak color paper and have coated several versions of the paper myself. I know how the reactions take place and know, in fact, that the cyan dye is completely formed in the color developer.

Kodak T1920 paper from about 1968 was the last color paper that relied on a bleach to form dye from leuco dye. Even this paper required ferricyanide bleach, as the ferric EDTA bleach was too weak to oxidize the leuco dye. In this case, the yellow dye was in the leuco form, not the cyan, and was oxidized to the color form.

Some papers can reverse this reaction in the presence of depleted blix and form leuco cyan dye. These prints are reddish after processing, and have retained silver and silver halide.

For a complete rundown on the chemistry see the US patent by Edens and VanCampen.

PE

Terence Spross · May 17, 2006

If this were film I'd be concerned that the stop bath isn't heated as I understand the grain size can become larger due to the temperature shift from warm to cooler at the stop bath. However I guess grain/dye cloud size is not a concern for print paper. When processing film I always made sure all baths (except the wash) was consistant, and so I did the same when I processed color paper. I always used an acid stop and had repeatable results.

Photo Engineer · May 17, 2006

Terence Spross said:
If this were film I'd be concerned that the stop bath isn't heated as I understand the grain size can become larger due to the temperature shift from warm to cooler at the stop bath. However I guess grain/dye cloud size is not a concern for print paper. When processing film I always made sure all baths (except the wash) was consistant, and so I did the same when I processed color paper. I always used an acid stop and had repeatable results.

AFAIK, grain size is not influenced by temperature changes. I have heard this and consider it a myth.

Can you cite a reference Terence?

If you cannot, I will continue to consider it a myth, as I never encountered it during my years developing photo products.

Thanks.

PE

using a stopbad with colour?

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