Ascorbic Acid / Effects On Fog & Stain Of Pyrocat-HD Negatives
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Let me comment further on this.
The addition of ascorbic acid is seen first as a loss of maximum density in the highest densities, not in the lowest densities, and even then only when measured by UV. For Blue sensitive processes the loss of stain is compensated by the greater energy provided by the synergism of ascorbic acid in the mix. The result is that for Blue sensitive processes there is never a reduction in maximum effective printing density with added ascorbic, even with loss of the stain.
However, to get more precisely on point, let me say this again. If you like the stain, which I value highly (especially for UV sensitive processes), do not add more than about 10-20 ml of a 1% solution of ascorbic acid per liter of working Pyrocat-HD solution.
Sandy
The addition of ascorbic acid is seen first as a loss of maximum density in the highest densities, not in the lowest densities, and even then only when measured by UV. For Blue sensitive processes the loss of stain is compensated by the greater energy provided by the synergism of ascorbic acid in the mix. The result is that for Blue sensitive processes there is never a reduction in maximum effective printing density with added ascorbic, even with loss of the stain.
However, to get more precisely on point, let me say this again. If you like the stain, which I value highly (especially for UV sensitive processes), do not add more than about 10-20 ml of a 1% solution of ascorbic acid per liter of working Pyrocat-HD solution.
Sandy
jdef said:
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With normal development, including minimal agitation, you don't need the ascorbic acid, and I don't advise it.
For Extreme Minimal Agitation and Semi-Stand the ascorbic acid may reduce slighlty B+F Stain with high speed films. Since B+F stain is just extra printing density, you might want to avoid it Especially with UV processes, since extra printing density with UV processes is on the order of minutes, not seconds as with silver processes. So the extra effort may be worth the trouble. But one way or the other, no big deal. Mainly, the biggest thing is to just expose your negatives well, and develop for the right time.
Sandy
For Extreme Minimal Agitation and Semi-Stand the ascorbic acid may reduce slighlty B+F Stain with high speed films. Since B+F stain is just extra printing density, you might want to avoid it Especially with UV processes, since extra printing density with UV processes is on the order of minutes, not seconds as with silver processes. So the extra effort may be worth the trouble. But one way or the other, no big deal. Mainly, the biggest thing is to just expose your negatives well, and develop for the right time.
Sandy
Flauvius said:
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