Effect of increasing sodium sulfite in D-23?

[Ulophot]

This may be a case of "If it ain't broke...."

According to my digital kitchen scale, my carefully levelled tablespoons of sodium sulfite amount to only 140 grams, not 200, for two liters of stock. I'm wondering what difference it would make to my development to add the remaining 60.

About a year ago, having found that my teaspoons of Metol were far short of weight, I bought a gem scale and started measuring it that way. I didn't think to weigh the sulfite, because it doesn't compress, as Metol does, so I figured the teaspoon recipe would hold for that part; and my little scale doesn't go up to even 100 g. Today, out of curiosity, I weighed.

My N development time for HP5 is 9 1/2 min @ 68, which is fine with me -- long enough for reliably even development, but not too long even for the plus developments.

If I needn't concern myself, I won't.

[paulbarden]

As you increase the amount of sulfite in a developer, it becomes more of a solvent type developer, and so sharpness decreases, but grain appears softer. D-23 is definitely in the camp of "soft" developers if you use the correct amount of sulfite. If you've been using less and like the result, then don't change it.

I recommend trying the Thornton 2-Bath variation on the theme - much better sharpness, lovely image tonality, and it makes for a negative that practically prints (or scans) itself. If you like D-23, then you owe it to yourself to try the Thornton 2-Bath as well.

[Michael R]

This may be a case of "If it ain't broke...."

According to my digital kitchen scale, my carefully levelled tablespoons of sodium sulfite amount to only 140 grams, not 200, for two liters of stock. I'm wondering what difference it would make to my development to add the remaining 60.

About a year ago, having found that my teaspoons of Metol were far short of weight, I bought a gem scale and started measuring it that way. I didn't think to weigh the sulfite, because it doesn't compress, as Metol does, so I figured the teaspoon recipe would hold for that part; and my little scale doesn't go up to even 100 g. Today, out of curiosity, I weighed.

My N development time for HP5 is 9 1/2 min @ 68, which is fine with me -- long enough for reliably even development, but not too long even for the plus developments.

If I needn't concern myself, I won't.

Depending on the state of your sulfite and all other things being equal, the effect of going from 70g sulfite to 100g sulfite should be a small increase in buffering strength and possibly a slight increase in pH. I doubt this would be significant enough to warrant a change in development time, but I haven't measured the pH with 70g sulfite instead of 100g so I really can't say anything more definitive, and in the end these things always need to be determined empirically (incidentally the target pH of D-23 is ~8).

100g sulfite will be a little more "solvent" than 70g, but whether or not there is any visible difference depends on magnification.

There's a lot of allowable slop in D-23 so I would not worry.

[Ulophot]

Much obliged, friends.

Paul, I have tested for times using divided D23 with the standard formula and, not having metaborate, plain borax. I haven't had occasion to use it much, and have not been thinking of using it to replace D23 1:1 for Normal. I haven't tested it extensively for grain, but was pleased enough to make it a first choice for 645 and 35 N-minus processing. If you have further thoughts on the Thornton brew per se, I'd be interested, here or via PM.

[tundra]

This may be a case of "If it ain't broke...."

According to my digital kitchen scale, my carefully levelled tablespoons of sodium sulfite amount to only 140 grams, not 200, for two liters of stock. I'm wondering what difference it would make to my development to add the remaining 60.

About a year ago, having found that my teaspoons of Metol were far short of weight, I bought a gem scale and started measuring it that way. I didn't think to weigh the sulfite, because it doesn't compress, as Metol does, so I figured the teaspoon recipe would hold for that part; and my little scale doesn't go up to even 100 g. Today, out of curiosity, I weighed.

My N development time for HP5 is 9 1/2 min @ 68, which is fine with me -- long enough for reliably even development, but not too long even for the plus developments.

If I needn't concern myself, I won't.

You have made the developer slightly less alkaline and slightly less of a solvent developer. So, you'll see effective film speed drop slightly but you'll get slightly sharper negatives with somewhat more pronounced grain. You may also have to increase development time a bit. In your case, the effect shouldn't be huge, but if you're concerned with consistency, stir in the remaining 60g.


D-23 is a marvelously malleable developer. I routinely use it in super-dilute concentrations for semistand and EMA development. This gives me very sharp negatives with excellent highlight management. I've gone as far as dilutions of 1+9, adding a little lye to bump up the alkalinity which is needed when you dilute that much. I get amazingly sharp negatives from this, though the increase in visible grain is really visible with 35mm. So, I do this only with sheet films.

In routine use, many people used D-23 at 1:2 or even 1:3 and get outstanding results. You just have to test to see what your preferred dilution yields in the way of effective film speed and what development time works best for you.

[ClaudioSz]

Hello! Can you write some parameters for EMA, please?

[Kevin Crisp]

OK, I'll ask: What is EMA development?

[Greg]

In the late 1970s till around 1990 I was using Edwal FG-7 (OK not D-23) 1:15 with a 9% Sodium Sulfite solution. Didn't have a scale so was measuring by eye. I'm sure my Sodium Sulfite solution ranged from maybe 5% to even 20%. With Ilford 120 film I honestly never saw any differences.

[tundra]

OK, I'll ask: What is EMA development?

It's a form of low agitation/high dilution development. My notes here:



https://gitbucket.tundraware.com/tun...nd-Development

[tokyo_blues]

As you increase the amount of sulfite in a developer, it becomes more of a solvent type developer, and so sharpness decreases, but grain appears softer. D-23 is definitely in the camp of "soft" developers if you use the correct amount of sulfite. If you've been using less and like the result, then don't change it.

I recommend trying the Thornton 2-Bath variation on the theme - much better sharpness, lovely image tonality, and it makes for a negative that practically prints (or scans) itself. If you like D-23, then you owe it to yourself to try the Thornton 2-Bath as well.

I use vanilla D23 regularly. It's currently my favourite developer, mostly in 35mm and 120. Used 1:1, I strongly disagree that it's in the camp of 'soft' developers. it's just as sharp as Adox D76. Actually, in a blind test, nobody would be able to tell it apart from Xtol, though with D23 I have to be about 1 spot more generous with exposure than with Xtol. Regardless, I personally find D23 1:1 achieves better tonality than D76 and Xtol with the film I use.

I have never tried any other flavours of D23 as what I like about it its the combination of extreme simplicity and incredible results with 400 ISO film.