The mystery of a developer developing, without a developing agent (ascorbic acid experiment)

[littlevisionary]

For a little background, I am a HS student who is trying to combine a love of film photography and chemistry by undertaking experiments with Chris Patton's E-72 ascorbic acid paper developer recipe for a final chemistry report. I'm using a 1+1 ratio, with no phenidone, so vitamin c is the only supposed developing agent (sodium sulfite 22.5g, ascorbic acid 9.5g [IV], sodium carbonate 45g, potassium bromide, 0.95g in a one-liter working solution).

The independent variable I am changing is the concentration of ascorbic acid (the dependent variable being the effect on the final image, though how I am quantifying that is a problem for another day). For my control group, I put no ascorbic acid into the developer solution.

To my total surprise, the image still developed. Albeit with very low contrast, but it was more than I was expecting (a blank sheet of paper!). I am not sure what happened, chemically. I had a theory one of the other components must have reduced the silver, but haven't found much evidence suggesting the other chemicals do this. I couldn't find too many others who are mixing developers..without developing agents.

Does anyone happen to know, or have any theories, about why this happened?

My scanned prints in order: 0g, 0.1g, 1g, 4.5g ascorbic acid (all with 8s exposure, f8, 60 sec in developing solution)


Many thanks!
A slightly stressed chemistry student

 

[relistan]

My guess would be either:

1. some contamination of either the trays or tongs
2. you have some paper with integral developer. What paper is it?

 

[esearing]

A salt print forms from just salt (sodium chloride or ammonium chloride) and silver nitrate and UV light. Modern printing paper will usually have developing agents in the emulsion which aid the developers, so exposing then submersing the paper in a carbonate solution would likely yield some result.

 

[Nicholas Lindan]

Use film for your experiments.

 

[Lachlan Young]

There can be small amounts of some developing agents incorporated into emulsion/ supercoat layers for various reasons (and not in the sense of 'developer-incorporated' papers that existed for a while).

 

[halfaman]

My experience with Ilford MG IV RC is very curious, it didn't matter what developer I used (Ilford Multigrade, Compard NE, even Tetenal Dokumol) because I ended always with the same contrast and tone.

 

[nmp]

Very interesting experiment....

sodium sulfite is also a reducing agent - so I wonder if it can do some development by itself as well. I am no photography chemistry expert so I can't be definitive. Take that out and see if it matches the control above. You can also add another control by simply exposing and fixing/washing the print without any development at all.

Good luck!

:Niranjan.

 

[pentaxuser]

My guess would be either:

1. some contamination of either the trays or tongs
2. you have some paper with integral developer. What paper is it?

If the OP scan's are faithful reproductions of the 4 prints then if the ascorbic acid is largely irrelevant to development, doesn't you two above reasons have to be pretty powerful i.e. the right and strong contamination and/or a lot of integral developer?

Scan 4 looked to be very good indeed

pentaxuser

 

[Nicholas Lindan]

My experience with Ilford MG IV RC is very curious, it didn't matter what developer I used (Ilford Multigrade, Compard NE, even Tetenal Dokumol) because I ended always with the same contrast and tone.

If the paper is developed to completion then, to first order, the results should be the same.

 

[littlevisionary]

It would be helpful to know what paper is being used.

A simple test for incorporated developing agents is to put a drop of plain alkali (sodium carbonate or stronger) on the paper in room light and see if it develops.

Incorporated developer is the only likely mechanism explaining the results of the experiment as described.

My guess would be either:

1. some contamination of either the trays or tongs
2. you have some paper with integral developer. What paper is it?

Thank you all for your suggestions! I had no idea incorporated developer existed, this seems like a promising explanation. I'm using ILFORD Multigrade IV RC DE LUXE (does the finish matter much? I believe I used pearl, will need to double check).

Is there any other way I can find out if it has an incorporated developer, other than the alkali test (does ILFORD publish such things, anywhere?)? I'm not back in school until February so won't have access to sodium carbonate, though I do have the paper still.

Assuming it does have an incorporated developer, does anyone have any paper suggestions which don't have it? I'd like to test one with my 0g ascorbic acid developer, as a part of the whole scientific process of hypothesise, then test.

I ruled out contamination because a part of my control variables is thoroughly cleaning out trays to avoid it. I did consider using film for my experiments, but paper seemed more forgiving, and far easier to conduct trials with because I could use the same negative over and over.

Very interesting experiment....

sodium sulfite is also a reducing agent - so I wonder if it can do some development by itself as well. I am no photography chemistry expert so I can't be definitive. Take that out and see if it matches the control above. You can also add another control by simply exposing and fixing/washing the print without any development at all.

Good luck!

:Niranjan.

Yes, I am planning to try these two ideas when I get back to the lab. Sodium sulfite seems like the most likely other candidate that reduces. Thanks again!

 

[Nicholas Lindan]

You can make S. Carbonate from S. Bicarbonate (baking soda). Just heat the baking soda in a pan until it stops 'bubbling;' the bubbles are Carbon Dioxide. Google for detailed directions.

Try using film as a guaranteed non-developer incorporated emulsion. If a snip of it turns dark in your developer then it works.

 

[MattKing]

Your paper doesn't incorporate developer, as that term is intended - i.e. it isn't paper that only requires an activator to create a developed image.
But your paper may incorporate trace amounts of fine tuning chemicals that will react with other chemicals in an environment of appropriate ph.
Those chemicals are designed to provide batch to batch consistency of speed and contrast when the paper is developed in, well, developer.
Nicholas' suggestion of film as an alternative is a good one for your tests.
You could probably also use home made emulsions.
One other thing to check - is the level of exposure similar to the exposure that would work with normal developer? If it is actually much greater, your paper mat be printing out.

 

[NedL]

Or just pre-soak the paper in water prior to your tests. On old MGIV paper ( the only one I tested this with ), straight sodium carbonate ( washing soda ) solution will develop a weak-ish image if the paper is put directly into it, but not if the paper is washed first....

A pretty fun way to play with this is just to do it with strips in normal room light.... so you know that "fully developed" = black.

 

[Raghu Kuvempunagar]

It is quite interesting that E-72 developer sans Metol/Phenidone can develop paper to completion in sixty seconds! Is there a price one has to pay in terms of print quality for omitting Metol/Phenidone from E-72?

 

[pentaxuser]

So if his paper(Ilford MGIV) doesn't have incorporated developer in it and that's also my understanding of it as well, can anyone say what ingredient or combination thereof that the OP has used that has given the very good scan 4 in his set of scans with increasing amounts of ascorbic acid, the last being 4.5g with what appears a normal time for exposure of 8 secs and normal development time of 60 secs?

Thanks

pentaxuser

 

[pentaxuser]

Ask Ilford. The emulsion must contain a silver halide reducing agent that works by chemical development. Functionally that would be a developer.

Thanks michael_r. Without wishing to sound combative my summary based on your response and that of others so far is that no-one who has responded really knows the answer. It remains a mystery.

As it is part of his academic treatise then the OP may receive more attention than I would from an inquiry to Ilford His knowledge looks as if Ilford could afford to be more technical in its reply to him than me

Ilford's technical dept may well be intrigued and curious as well to find an answer. I hope so. It's a mystery that deserves to be solved

pentaxuser

 

[relistan]

Thank you all for your suggestions! I had no idea incorporated developer existed, this seems like a promising explanation. I'm using ILFORD Multigrade IV RC DE LUXE (does the finish matter much? I believe I used pearl, will need to double check).

Is there any other way I can find out if it has an incorporated developer, other than the alkali test (does ILFORD publish such things, anywhere?)? I'm not back in school until February so won't have access to sodium carbonate, though I do have the paper still.

Assuming it does have an incorporated developer, does anyone have any paper suggestions which don't have it? I'd like to test one with my 0g ascorbic acid developer, as a part of the whole scientific process of hypothesise, then test.

I ruled out contamination because a part of my control variables is thoroughly cleaning out trays to avoid it. I did consider using film for my experiments, but paper seemed more forgiving, and far easier to conduct trials with because I could use the same negative over and over.



Yes, I am planning to try these two ideas when I get back to the lab. Sodium sulfite seems like the most likely other candidate that reduces. Thanks again!

If you want to test sooner, you can make sodium carbonate from baking soda as described above, or buy it as washing soda or "soda crystals" (depending on where you live) for very cheap in the super market laundry aisle.

 

[Lachlan Young]

It remains a mystery.

Not really - they seem to be used in some coating packages for various reasons (stabiliser/ preservative from what I recall). This is different to developer incorporation which used much larger quantities (and other ingredients) and would develop fully to completion if put into a solution of sodium hydroxide.

 

[nmp]

Try your local Walmart, for example:

https://www.walmart.com/ip/Arm-Hamm...rgent-Booster-Household-Cleaner-55oz/19407690

 

[pentaxuser]

Not really - they seem to be used in some coating packages for various reasons (stabiliser/ preservative from what I recall). This is different to developer incorporation which used much larger quantities (and other ingredients) and would develop fully to completion if put into a solution of sodium hydroxide.

Thanks. Can you expand on this? I think you are referring to the paper which has some form of stabiliser/ preservative coating in it which accounts for what seems to me to be a remarkable print but I may have misunderstood you.

So has the OP found by experiment a developer which seems to work as well as "normal" paper developer?

Thanks

pentaxuser

 

[Lachlan Young]

some form of stabiliser/ preservative coating in it which accounts for what seems to me to be a remarkable print but I may have misunderstood you.

Without a comparison print (and step wedge exposures too, preferably) done with the same paper and a regular commercial paper developer, we have no meaningful way of understanding in a meaningful/ sensitometric way if the print on the right is 'good', let alone how many grades adrift it is from the same paper in something like PQ Universal. Furthermore, we have no indication if the effect is repeatable with multiple sheets through the same solution, or a whole long list of other variables that need to be controlled/ normalised. As for why Ilford put the reducing agent in, as I said above, it's likely there to help the shelf stability of the product - and not so that you can stick it into an alkali solution with some ascorbic acid in it & get an image to appear.

 

[NedL]

I have no idea where the thread is now, but I had some back and forth with PE about this a few years ago, and he had found the same thing: weak and very fast development of MGIV in just alkali. It's not incorporated developer like the old "self developing" papers, but there's something in there... whatever it is exhausts quickly before full development happens ( which is what I was interested in... I wanted very weak development of lumen prints and solargraphs, which are hugely overexposed paper -- and the amount of development was controllable by varying the pH -- it worked very well for my purpose )

 

[Raghu Kuvempunagar]

So has the OP found by experiment a developer which seems to work as well as "normal" paper developer?

You might not have seen this thread.

 

[pentaxuser]

A very interesting article, Raghu and thanks. If anything I preferred his scan of the Vitamin C developed print which for those still curious, was made on Ilford MGIV as per our OP's experiment. Edit: I have since returned to the article and it was Adorama Variable Contrast paper. I have no idea who makes this paper for Adorama nor if it incorporates a developer in it so this vital piece of info remains unknown. What we do know if that our OP's paper was definitely Ilford MGIV. The author i.e.Gasperi also seems to have evidence of its ability to develop over several days and do as many as 16 x4x5 prints so it would appear to match the requirements that most of us need to be met when printing.

He was developing paper negs and this prompted Doremus Scudder to wonder if paper neg printing would successfully translate to paper positives under a neg projection but the OP appears to have managed this and I cannot think what might be the difference between the paper neg printing process and the enlarger print process that might prevent successful transition from the former done by Gasperi from the Large Format forum and our OP

Finally Lachan suggests that there is no way we can know in a sensitometric way if the OP's print is good and he is right as such material has not been provided to us and the same applies to Gasperi's paper negs but unless the actual paper negs and positives have been manipulated either by overt intent or by covert scan software then it would appear that they "work"

Lachlan mentions that repeatability remains unknown but thanks to Raghu's link it would appear that Gasperi's experience does suggest that results are repeatable

I still cannot dismiss the feeling that the OP may have found something here

Wasn't Einstein's opinion of the theory of the then new "upstart" of quantum mechanics based on the premise that God doesn't play dice with the Universe because it led to such incredulous conclusions about the behaviour of sub atomic particles?

Now quantum mechanics has been accepted as the current "truth" because it works

pentaxuser

 

[Lachlan Young]

I still cannot dismiss the feeling that the OP may have found something here

No, there's nothing 'new' about his findings. Testing for reducing agents in emulsion/ supercoat structures has been done for decades. And furthermore, anything you think is 'new' about Ascorbic Acid etc as a developing agent was discovered decades ago - the issue was getting them to work well and reliably, and that needed the advent of DTPA and similar sequestrants. A couple of small scale pieces of anecdotal evidence does not make a case for anything at all - especially as manufacturing R&D will have gone over the product with a finer toothed comb than you will ever have access to (and Ilford used to make fully developer incorporated papers - labelled as such), and did not recommend the courses of action you seem so obsessed with, so you need to ask yourself what chemical (not economic) reasons lie behind this. Remember too that whatever happens with a small scrap of paper may not translate into a 16x20" let alone a 40x50" print.