PC-TEA + Sulfite

[Alan Johnson]

Is it practicable to add sodium sulfite to PC-TEA 1:50 to produce a solvent developer? My ancient copy of Developing by C.I.Jacobson gives the pH of a 10% solution of sodium sulfite as 9.7. There is PC-TEA-TOL:
www.apug.org/forums/article.php?a=184
But the object there,to produce a developer like Mytol/Xtol by increasing phenidone concentration,appears different. Thanks.

 

[gainer]

It has been done, but I don't know if it is a solvent developer. Start with 10 grams/liter of working solution and compare with none. Add more if you find it helps. Sulfite concentration is not the only variable affecting "solvent" action. See Ryuji Suzuki's site for more discussion.
Whether you call it solvent or not, some like PC-TEA better with a bit of sulfite.

 

[Alan Johnson]

Thanks,Patrick. This will only be for a few portraits I hope to do, for landscapes I use the sulfite free version. A useful dual purpose developer if the sulfite addition works.

 

[Gerald Koch]

The maximum solvency effect of sulfite is at a concentration of about 7% and not at 10%.

 

[Jordan]

Alan, in coming up with "PC-TEA-TOL", my objective was to find a way to use the PC-TEA stock to make a more traditional, solventy developer, a la Xtol -- so the PC-TEA could be used in two different ways as needed.

I arrived at the "PC-TEA-TOL" formula by taking a concentrated PC-TEA solution (about 1+13, which gives the same phenidone concentration as stock Xtol) and adding sodium metabisulfite until the pH of the solution reached 8.2 (the same pH as stock Xtol). The result of this is that "PC-TEA-TOL" can be used with Xtol times (or the working solution can be diluted 1+1 and used with Xtol 1+1 times) with pretty good reliability. The negatives have fine grain and good sharpness.

The reason I used sodium metabisulfite instead of sodium sulfite for "PC-TEA-TOL" is because working solutions of PC-TEA are quite alkaline. To bring the pH of the concentrated PC-TEA solution down to something like Xtol's, I needed an acidic source of sulfite, and metabisulfite fits the bill.

I find myself using the other version listed on that page ("PC-Gly-TOL") more often, simply because it's usually PC-Glycol that I have around. (When I need PC-TEA, I simply dilute PC-Glycol 1+1+50 with TEA and water.) "PC-Gly-TOL" also works very well and I use it quite often.

You should note that the amount of sodium metabisulfite quoted for "PC-TEA-TOL" assumes that you are using Patrick's "original" PC-TEA recipe (10 g ascorbic acid, 0.2 g phenidone in 100 ml TEA), which is different than the one that eventually got published in Photo Techniques. If you use a different PC-TEA formula, you'll need to adjust your times.

Let me know if you have any more questions...

 

[nworth]

... Sulfite concentration is not the only variable affecting "solvent" action. See Ryuji Suzuki's site for more discussion.
Whether you call it solvent or not, some like PC-TEA better with a bit of sulfite.

One of the reasons for this is that sulfite affects the shape and agglomeration of the developed silver particles. This may be more imprtant than the actual solvent action (although it is probably due to the solvent action). Sulfite also increases the effective emulsion speed some.

 

[Alan Johnson]

My tests suggest that adding sodium sulfite to PC-TEA 1:100 is not a successful approach.
I developed Delta 100 17.5min 68F in PC-TEA 1:100 containing 0,10,30,70 g/L sodium sulfite and made 11x prints.Several times,after shuffling the prints up I picked out the one with the least grain.It was always the 0 or 10 g/L sulfite.
PC-TEA 1:100 is a good acutance developer but apparently cannot be made a solvent developer just by adding sodium sulfite.

 

[Photo Engineer]

To get a suitable solvent action from sulfite, you will probably need about 25 grams / liter minimum in the working solution. Below that level, the solvent action of sulfite falls off rapidly.

PE

 

[Alan Johnson]

PE, that's why I was expecting smaller grain with 30g/L or 70g/L sulfite but my results did not support the theory.All I can think of is that the pH may have been raised.

 

[Jordan]

PE, that's why I was expecting smaller grain with 30g/L or 70g/L sulfite but my results did not support the theory.All I can think of is that the pH may have been raised.

Sodium sulfite is the salt of a weak acid and so does raise the pH of its solutions. The main reason I use sodium metabisulfite (an acid source of sulfite) in my "PC-TEA-TOL" concoction is to avoid making the developer even more alkaline.

 

[Ryuji]

The maximum solvency effect of sulfite is at a concentration of about 7% and not at 10%.

Not necessarily true. This number depends on the type of emulsion, bromide concentration, and a number of other factors.

 

[Ryuji]

PE, that's why I was expecting smaller grain with 30g/L or 70g/L sulfite but my results did not support the theory.All I can think of is that the pH may have been raised.

It should be noted that "solvent" does not imply "finer grain." These things are separate issues, although a lot of darkroom instruction books incorrectly use these terms almost exchangerably. It's very easy to make a solvent developer that is grainier than non-solvent counterpart, and there are several examples of well known formulae of this kind. Kodak D-19 is a good example. (D-19 is a very solvent developer and it produces very grainy image.)

 

[Alan Johnson]

For the record,I tried lowering the pH. I used PC-TEA 1:100 in 50g/L sodium sulfite and 4g/L sodium metabisulfite,which gave a pH about 8 with a pH paper. I developed Delta 100 in this 24min 68F. The grain was somewhat reduced compared with the previous results with 30 and 70g/L sodium sulfite (pH about 9.5) but still larger than that in PC-TEA with no sulfite added.
The PC-TEA 1:100 contained 0.025g/L phenidone compared to 0.15g/L in Mytol. It seems that the solvent effect is not found at the lower phenidone concentration when sulfite is present.