> But are you saying that the HCA bath consists only of 2% Sodium Sulphite?(posted 8617 days ago)Yep. The common HCAs are similar, usually with a little sodium bisulfite; I believe that's Kodak's official HCA formula. I've used it both ways with no discernible difference.
> If that's the case, I can't understand why the stain was still there when I was using D76
No idea on that. Occasionally I've developed test films without bothering with HCA in a variety of developers including D-76 and haven't noticed any difference in how much dye is left between developer types.