Maximum speed split developer. And effect of more Phenidone?

[Mark Crabtree]

I was actually thinking the B bath I made was to have carbonate, but I think I copied the right one to this thread. I do know that I used metaborate, so I suppose this is the right one.

I do remember mention of a carbonate B bath with the consequences you mention. I had carbonate laid out, but only turned up this formula and a borax one that evening. I may look into that more.

It looks like I'll need a similar treatment for two rolls I shot tonight, so will have some more chance to experiment. It was better light though and I could probably get by with Acufine or similar, but it is a chance to refine this setup, and I liked the results I got. I was able to get f2 at this venue, and still expect a half stop more deep shadow exposure than last time, which should make a world of difference. It will probably be Sunday night again when I get a chance to mess around with this since I won't feel comfortable without a test run.

 

[Mark Crabtree]

I finally did some tests Sunday night and was surprised by the results. On a test roll (all results are Tri-X 35mm) I doubled the Phenidone which I realize is extreme, but I like to surround a problem rather than sneak up on it.

One time through the A/B baths showed a bit more highlight density, but no apparent increase in shadow detail or base fog.

Them I tried twice through each bath - A/B, running water rinse, A/B - as I had been doing with the original formula with some success. This gave more highlight density than my control roll that had extended development in Xtol, but had no more shadow detail. So I lost the benefit of the compensating effect that I had been getting. It was very much of a typical "pushed to 1600" look, though still very fine grain.

I still had very low base fog, but a detectable amount more than before. My impression was that I actually had slightly less shadow detail than before; maybe the equivalent of 1/3 stop exposure. Not at all what I expected, though someone in this thread thought that might happen. My test roll shots are the same conditions as before, but not tightly controlled enough that I can be absolutely confident of that judgement.

I really want to try some Diafine before my next event, but the NYC stores are closed for Passover so I can't get it in time from them. Freestyle only has gallons. I will probably revert to the original formula, which did give good results. In the meantime I might up the Hydroquinone proportionately just out of curiosity to see what effect that has.

 

[Mark Crabtree]

That is what I was using for some difficult situations a bit over 20 years ago, but mostly for contrast control. I did not see much improvement in shadow detail. I also saw more highlight compression than I wanted and eventually moved to Acufine, which gave me a slight boost in speed over D-76, plus less highlight contrast (more shouldering). I eventually moved almost entirely to Xtol, which is hard to beat as an around developer.

Now I'm looking for maximum shadow detail (speed), but while keeping the highlight density manageable.

 

[Gerald C Koch]

All the aliphatic alcohols (methyl, ethyl, isopropyl, butyl, ...) are toxic to a greater or lesser degree. Drink enough whiskey and you're dead. The principle cause of poisoning would be by ingestion. The same can be said about most photographic solutions. Methyl alcohol is a good solvent for Phenidone and similar chemicals and more readily available than other suitable solvents. Methyl alcohol is normally found in the human body in small amounts as a product of metabolism. Again as with all poisons it is a matter of dosage.

 

[Rudeofus]

All the aliphatic alcohols (methyl, ethyl, isopropyl, butyl, ...) are toxic to a greater or lesser degree. Drink enough whiskey and you're dead. The principle cause of poisoning would be by ingestion. The same can be said about most photographic solutions. Methyl alcohol is a good solvent for Phenidone and similar chemicals and more readily available than other suitable solvents. Methyl alcohol is normally found in the human body in small amounts as a product of metabolism. Again as with all poisons it is a matter of dosage.

In the case of Methanol, dosage seem to be a serious problem. According to the wikipedia entry for Methanol, "If as little as 10 mL of pure methanol is ingested, for example, it can break down into formic acid, which can cause permanent blindness by destruction of the optic nerve, and 30 mL is potentially fatal ..." and "... methanol (whether it enters the body by ingestion, inhalation, or absorption through the skin) can be fatal ..."

I have used Methanol and am still alive, but generally try to minimize my exposure to it. Most APUGers here (including myself) lack a fume hood or other protective equipment that is frequently (and with reason) recommended for handling such compounds. I would therefore recommend against using, or at least avoiding them if possible, compounds that create toxic fumes, dust or which are toxic in minimal doses. In computer security we call this "defense in depth" ...

 

[Gerald C Koch]

One must always weigh the risk involved in the use of any chemical. However the risk in making and using methyl alcohol solutions of Phenidone is exceedingly small.