Pyro in the May/June "Photo Techniques"

[Kevin M Bourque]

The May/June “Photo Techniques” contains an article by Howard Bond in which he compares Pyro to D76. He shot several identical high-contrast scenes (snow on mountains) on 5x7 T-Max 100 and compared the resulting prints at 4.5x enlargement.

According to him, the prints are identical in terms of sharpness, and nearly the same in tonal range. He is convinced that a little extra work would make them identical. He ends that article by asking to see similar pairs of prints that show a substantial difference between pyro and any other developer.

He also raises some questions about the possible toxic effects of pyro.

Clearly, he sees no reason to use the stuff, and is asking for a careful, experienced printer to show him why Pyro is special.

[Ken Lee]

Howard Bond seems to have drawn an unfortunate and misleading conclusion. Out of all possible films with which to test Pyro, he chose the one most widely rejected for use with that kind of developer.

Had he chosen almost any other film, his comparison would have probably reached the same conclusion reached by several respected researchers, already in print and freely available on the web.

[Richard K.]

T-Max 100 has got to be the worst choice for gleaning Pyro effects since they are so minimal with this film. Not that Mr. Bond is necessarily wrong, but just about any other film (including T-Max 400) would have been a better choice and provided enhanced basis for comparison.

[Jorge Gasteazoro]

He is convinced that a little extra work would make them identical.

This is exactly the point, why work harder when you can use a developer that allows you not to. There is no doubt n my mind that you can make them work the same, but then the idea is to get a better neg with less work, no?

[Jorge Gasteazoro]

You know, now that I think about it, there might be a reason why pyro developers are better. Since the light tones in the negative have less silver and part of the density comes from the stain, it might be that given a certain developing time to build the high tones might also build the middle tones a little bit more, thus giving better separation for the middle tones as well.

This is just speculation and I will try some tests to see if this is true. It might not be, but sounds reasonable.

[bob moulton]

Question for those who read the article: How do advocates of the various forms of pyro respond to the charges about toxicity? i agree that bond could have chosen a different film for his testing. But so far no one has addressed his concerns about the dangers of the chemistry. How come? Are Bond and the sources on which he relied wrong?

[David A. Goldfarb]

I also have to agree that the film choice is just wrong, if he was looking to produce an interesting result. Pyro is great with Tri-X and Efke PL100 in my experience, but when I shoot TMX, I prefer D-76 (1+1).

[Jorge Gasteazoro]

Question for those who read the article: How do advocates of the various forms of pyro respond to the charges about toxicity? i agree that bond could have chosen a different film for his testing. But so far no one has addressed his concerns about the dangers of the chemistry. How come? Are Bond and the sources on which he relied wrong?



They are not wrong, they are simply exaggerated, let me give you an example. Hydroquinone, a developer that nobody fears, most people stick their hands in it and nobody has ever said is toxic has the chemical formula of p-dihydroxybenzene. Pyrogallol OTOH is hailed as the poison bane and people warn your arm will fall off if you stick your hand in the developer, yet the chemical formula is 1,2,3 trihydroxybenzene, furthermore catechol is o-dihydroxybenzene. It is not clear if the position of the hydroxy groups aids or prevents absorption through the skin, but I would doubt the difference would be so great as to make any difference in the toxicity.



The problem that arises from using pyro or catechol is that most of the time it has to be mixed from raw ingredients, as such the possibility of inhaling the chemical is greater than using a mixed developer. I am not aware of any studies but given the chemical formulas and properties I would say if you inhale hydroquinone you would be in as much danger of intoxication as if you inhale pyrogallol or catechol, yet nobody says anything about hydroquinone.



This was also magnified by that woman who published a book on darkroom toxicity which was full of errors and exaggerations. People without a chemical background as well as health and safety read this book and continued to propagate the myth that pyrogallol is more toxic than the usual photographic chemicals. This is wrong, let me put it this way, no benzene derivative is good for you, most photo developers are benzene derivatives, so you certainly do not want to use them to make soup, but with normal care and sound lab practices, pyrogallol and catechol are not any more toxic than your run of the mill paper or film developer.

[Gem Singer]

Hi Jorge,

The literature seems to be filled with cautionary statements regarding the rate of absorption through the skin of pyro compounds, as compared to other combinations of developing agents. They say that pyro absorbs very quickly. Any truth to that? They always caution the user to wear Nitrile gloves. Latex gloves don't afford enough protection. Are the people who make those statements merely being over cautious?

[steve simmons]

Many people who claim a staining developer makes no difference use T-Max and assume that film is representative. It is not. Use a real film such as FP4+, HP5+, Tri-X, etc. and I defy the printer with a sensitive eye not to see the difference.

It frequently appears to me that those who poo-poo a staining developer have built a career selling prints without it and do not want to admit there may have been a better way than what they've done. Others sell some type of competing products.

As for the toxicity many people develop a reaction to metol and can no longer place their fingers in a metol developer. All photo chemicals need proper ventilation. If handled carefully staining developers can be used safely.

steve simmons