Ascorbic acid developers

I like to experiment and ruin my film once a while :).

 

Assuming I am trying to mix Mytol or a similar developer, I need 13

grams of sodium ascorbate for 1 liter of solution. I don't have sodium

ascorbate. If I make my ascorbate from ascorbic acid bought at the

pharmacy, how many grams of ascorbic acid and baking soda do I need to

make 13 grams of ascorbate? How do I measure without scales?

 

Does anyone know how many grams of ascorbate is in the official Xtol

formula? I still have Xtol left, and would like to mix it with

ascorbate without mixing sulfite from packet B, so I can get very

sharp and probably big grain (or whatever else it does to my

negatives, it's all good). The packet B actually contains sulfite and

ascorbate, not just sulfite.

 

Thanks!

Why not try PC-TEA? No sodium ascorbate, no sulfite. Simple, effective, and lasts forever.

 

PC-TEA

 

ascorbic acid 9

 

phenidone .2g

 

triethanolamine 100ml

 

Jay

The formula that I have for Mytol calls for 12g Sodium Ascorbate / L. (p.157 Anchell, 2nd edition)<br><br>

 

To get 12g of Sodium Ascorbate I mix separately as follows for Mytol:<br><br>

 

120ml Distilled Water @ 100F<br>

5.1g Sodium Bicarbonate (dissolve completely)<br>

10.7g Ascorbic Acid (added slowly, it 'fizzes' quite a bit)<br><br>

 

Order of mixing is important, always add the Baking Soda first.

 

Hope this helps, I do not have teaspoon equivalents for these chemicals.

I'm using this right now. Low pH and extremely fine grain on Delta 400. Not recomended for Tri-X, because the solvent action is too high. Mix just before use.

 

1l water

 

64g sodium sulfite

 

2.8 g ascorbic acid

 

10 g boric acid

 

2 ml phenidone 1% solution

 

 

D400 74F 12.5 mins. Note that mixing the sulfite will raise solution temp. by 2F.

I agree with Jay on this one. PC-TEA is easier to mix, lasts much longer, costs less and works nicely with many films. I think my formula has 10 grams of ascorbic acid and .25 grams of phenidone. Patrick Gainer has written about using ascorbic acid (vitamin C) vs. sodium ascorbate. Perhaps he will give you a conversion figure if one is needed.

 

Jeff

The amount of phenidone or metol in such a developer is more critical than the amount of ascorbate. Once the weight ratio is above 40:1 ascorbate: phenidone or 4:1 ascorbate to metol, the activity changes little.

A given weight of ascorbic acid will give 1.125 that weight of sodium ascorbate.

1 teaspoon (5 ml) of ascorbic acid = 4 grams. 1 teaspoon of ascorbic acid + 1/2 teaspoon of baking soda = 4.5 grams of sodium ascorbate + lots of CO2. If you use too much water in mixing, enough of the CO2 will remain in solution to change the pH. Use very little warm water to mix the ascorbic acid and baking soda and let the effervescence subside before adding it to the rest of the developer.

What you need, then, is 4 tsp ascorbic acid powder and 2 tsp baking soda in about 50 ml of water. Put it in a big container, put the water and ascorbic acid in first, and slowly add the baking soda or stuff will fly all over the place.

PC-TEA is next after I am done with Xperimental Xtol/Mytol.

 

Thanks very much Patric.

Jeff,

 

I make mine up the same way (10g ascorbic acid, .25g phenidone), and I don't remember exactly how or why I deviated from the official formula, but since I made up a liter of the stuff the first time, I've developed a lot of film with that formula, and I don't want to mess with a good thing by reverting to the correct formula. Maybe Pat will tell us what we're missing by mixing it the way we do.

 

Jay

I can't say you're missing anything. You've done the tests and got the results you like. What more could you ask for?

 

I think I used 9 grams because I had difficulty dissolving 10. Since then I have found out that a little bit of water doesn't hurt anything and it makes dissolving a lot easier at much lower temperature. 10 ml hot water, 10 grams ascorbic acid, 0.25 grams phenidone. This, believe it or not, will dissolve. Add the TEA to make 100 ml. Warming it makes it dissolve today, but you shouldn't have to go over 150 F.

Based on my limited experience, you'll find that Mytol gives "softer" (but not "mushy") negs than the sulfite-free developers. Depending on your film and shooting habits, you may find this helpful or harmful. I would advise mixing up the Mytol entirely with deionized water and checking it on inconsequential film before using it for anything important.

If you have PC-TEA and feel the need of sulfite, you can always dilute the PC-TEA stock with a sulfite solution. That way you can have your cake and eat it too.