Why so much Sulfite?

[BradS]

Why do so many B&W film developers contain so much sulfite? Is it because, historically, devs like D-76 (with 100g/Liter) were used in replenished deep tanks?

 

[Photo Engineer]

Sulfite is a preservative and mild solvent which gives better image quality.

PE

 

[BradS]

Sulfite is a preservative and mild solvent which gives better image quality.

PE

Well, yes. I understand that but, wouldn't 25 or 30 g/Liter be sufficient to preserve a liter of D-76 or D-23 if the solution is to be used one shot?

 

[Photo Engineer]

Make one up and test it. Seeing the results might explain it better.

PE

 

[BradS]

Make one up and test it. Seeing the results might explain it better.

PE

Point taken. Will do. Thanks.

 

[Anscojohn]

Brad,
The sulfite in D23 has multiple functions, as others who know photochemistry can better tell you. My understanding is that it is a real triple threat: preservative, alkali source, and silver solvent. Although I know little about photo chemistry, D23 has been my film developer of choice for many years and I know that some people dilute the stock 1:1, which would give 50 grams per liter. I think it can even be used 1:3 which really get's the sulfite content down there. Once diluted, though, it should be used and thrown away. I SUSPECT that mixing stock with less than the 10% solution would not keep very long--but I would rely on chemical experts, which I am not. I know for a fact that D23 stock lasts a long time in a tightly sealed bottle. I found some unused D23 not long ago--mixed up in 1999--it still worked fine when I tested it.
John, Mount Vernon, Virginia USA

 

[jim appleyard]

If you're looking for (and I'm not sure of the point of your question) a dev with less sulfite, Anchell's "Darkroom Cookbook" has several.

 

[BradS]

hmmm, yes. What is the point of my question...well, I guess....it all comes down to the desire to reduce the cost of a liter of homebrew D-23 (or, something like it).

I have been using D-23 on and off for about a year now and, I keep thinking about the cost of a liter. The simple fact is that a liter of home brew D-23 costs a little more than a liter of pre-packaged Kodak D-76. Since I have a pound of Metol and I like D-23, I'm going to keep mixing my own but, I look for ways to reduce the cost while still maintaining the quality...

In prior experiments, I've reduced the Metol to 3g / liter and the sulfite to as little as 75 g/liter with good results but, I want it to be less expensive still.

In another thread, I asked about the Hydroquinone in D-76...with much the same motivation. I think that some of the motivation for the Hydroquinone in D-76 is to reduce the cost (the manufacturer's cost that is).

 

[Anscojohn]

Brad,

DK25R.

John, Mount Vernon, Virginia USA

 

[David A. Goldfarb]

You need a certain concentration of sulfite in the working solution to get the solvent effect. I forget the percentage, but I think Anchell mentions it in _The Darkroom Cookbook_, and I know it's in Haist, but my copy of Haist isn't handy at the moment. This is why a developer like D-76 acts like a solvent developer and produces finer grain at full strength or 1+1, but produces coarser grain and higher acutance at 1+3.

If you reduce the sulfite with D-23, I suspect you'll get the same effect--more grain, more acutance.

 

[BradS]

Brad,

DK25R.

John, Mount Vernon, Virginia USA

yeah. Been there. Done that. When the the working solution gets really dingy looking, it makes me...well...not feel too good about putting my film in it. I wish I had a set of deep tanks -- like in the darkrooms aboard Navy Aircraft Carriers.

But, I have to agree, it does work wonderfully.

Even un-replenished, D-23 gives beautiful results. I like it "seasoned" but not dingy. When metallic silver starts to fall out of solution, I do a few more sheets of film and then make fresh.

 

[jimgalli]

Brad, I've tweaked the Ansco 135 fomula to make a single 850ml batch that's already 2:1 dilution for one shot use. It uses 10G Sodium Sulfite and 10 G Sodium Carbonate. Very cheap. And if you're called away prematurely (as family men often are) it pours into an empty wine bottle and keeps for about 6 weeks with no air space. That's why I did it in the size I did. 135 is for slightly warm tones.

 

[Nick Zentena]

D-23 works fine at 1:3. IIRC there is a different developer that is almost the exact same formula as D-23 1:3 [Winchel?].

But at 1:3 it will be different then at stock. I'm all in favour of lower cost but considering the cost of film etc the first choice has to be the way things look. No?

A better way to lower cost IMHO instead of changing formulas is to buy your chemicals in larger bags. Price per kg goes down quite a bit the more you buy.

 

[markbb]

Just how much does a litre of developer cost you, and how much film will it process?

 

[dancqu]

In prior experiments, I've reduced the Metol to 3g / liter
and the sulfite to as little as 75 g/liter with good results
but, I want it to be less expensive still.

On a liter basis I use 1 and 10 grams metol and sulfite;
half liter per 120 roll. My D-23 is an 8-80/liter on a full
strength basis. I've not tested below 10 grams/liter
working strength but think 5 or even less may do.

A half liter of .3, .9, .9 grams metol, sulfite, and
carbonate gave more than enough development.
Those are the ingredient ratios for Ansco 120.

If you're in a devil may care mood you might try
a liter at .5, 5, metol, sulfite. Slow film and 20
minutes. Doesn't take much. Don't need or
want the solvent effect? Carbonate. Dan

 

[Alan Johnson]

Why do so many B&W film developers contain so much sulfite? Is it because, historically, devs like D-76 (with 100g/Liter) were used in replenished deep tanks?

It seems the high sulfite is needed to obtain the solvent action.G.W.Crawley, BJP Dec 16 1960,found the solvent action became detectable at about 45 g/L sulfite.
In 1902 'The Metol Developer' had about 30 g/L sulfite in the working solution,see p0294 below, they do not seem to have recognised the solvent effect at that time. Perhaps Kodak discovered it.
www.rodsmith.org.uk/photographic-dictionary/index.html

 

[jim appleyard]

Brad, check out cost of devs, a bit out date with prices, but perhaps it's all relative:http://unblinkingeye.com/Articles/Developers/Cost/cost.html

TryD-76H, or a variation. D-76 uses less metol than D-23, and when you cut out the H, it costs even less. You can cut the sulfite as low as you want.

There's also the Beutler Formula, FX-1 and Windisch D-23, 1+3.

 

[analogfotog]

Check out this link, for a very interesting article on D-76, and its many variations: http://silvergrain.org/wiki/D-76.

There is some good information about how developers like Ansco 17, particularly about the sulfite concentration.

 

[analogfotog]

That should have been, "...about how developers like Ansco 17 came to be developed..." Pun intended.

Sheesh! And I'm the person who deplores sloppy grammar!!

 

[dpurdy]

One way to reduce the cost of Sodium sulfite is to buy it bulk from a chemical supply house. I use a lot of it for paper developer and for hypo clear and buy it in 60 pound bags for about a dollar a pound. Less than a third what it costs in a photo store. You might be able to get sodium carbonate the same way.

 

[Brook]

I bought a 50 lb bag from a local commerical pool supply company for about a buck a pound. They also have 50 lb bags of hypo and sodium carbonate. Also look for places that service big boilers for heating old commerical buildings, they use it as an oxygen scavenger in the boilers. I saw the kodak stuff going for about $10.00/lb at the local photoshop.

 

[dpurdy]

That is a great tip. I am guessing the hypo is the sodium hypo thiosulfate.

 

[Brook]

The hypo bags say "sodium thiosulfate, prismatic rice, photo grade". It works just fine. I find I can fit just about a whole bag in a 5 gallon bucket, and use a screw on lid with a gasket, got it at the local big box hardware store.

Look for places that are right on the railroad tracks, they buy by the boxcar load. The sales people are usually clueless, but there should be a guy in the back who knows everything, you must speak to him.

 

[BradS]

Make one up and test it. Seeing the results might explain it better.

PE

So I did and here is a brief summary of the experiment and some results...

I mixed up two developers. Developer A is: 10g Metol, 100g Sulfite, 8g Borax and water to make 1 liter. Developer B is the same as developer A except that B has only 25g sulfite per liter.

I shot six sheets of fresh Illford FP4+ rated at box speed. Both sheets on either side of a film holder were exposed exactly the same and, of course, were of the same scene at nearly the same time and same light. Two scenes have what I consider to be flat light and the third scene is contrasty afternoon sunlight.

One sheet from each film holder was developed in Dev. A and the other sheet in dev. B. In both cases, the dev time was 8 minutes with continuous rotational agitation. I used a Jobo Expert drum on a unicolor roller base with the direction reversing switch bypassed (so, it never changes direction).

Examining the negatives it is immediately apparent that dev. A built up more negative density and that dev. B wasn't able to hold the shadow detail.

Some scans follow - these are unadulterated negative scans - please forgive the crudity of the presentation - I simply scan, rotate, remove the color and save. Nothing more.


Dev A is on the left.

These were done with a crown graphic and 150mm Xenar in flat lighting.

 

[BradS]

dev A is again on the left.

Modern, multicoated and super contrasty 1355 Nikkor-W in harsh light.