Pyro-Glycin-TEA

[derevaun]

I've searched the photoformulary site but I can't find any glycinyro for sale.

 

[clay]

starting times for Fp-4 at 1:100 in the 8 min (70deg) range???

 

[jim appleyard]

Jay, what activates it? Is the TEA alkaline enough? I was under the impression that TEA was merely a good "storage" device. I believe I will take your word for it. I can't keep up with you!

 

[sanking]

Some of Barry Thornton's formulas apparently contain glycin, but since they are proprietary there is no way to know exactly which ones, and how much, or what glycin is in combination with. However, I am fairly certain that one of them contains both phenidone and glycin with pyrocatechin.

I have tested glycin in the Pyrocat-HD formula, both as an addition with phenidone and in place of phenidone. As an addition it makes the formula much more active without changing the stain or grain. In place of phenidone the formula is less active and grain size appears larger, but sharpness is bitting, rather like DiXactol.


What do you mean by an upsweeping curve? Is this based on a curve resulting from a densitometer reading (if so, what color light?), or is based on the affect on VC papers? I did not observe the upsweeping curve you mention in my plots, though my analysis was based on blue and UV for graded papers and alternative printing and did not make any printing tests with VC papers.

Sandy

I've been testing a pyro-glycin-TEA developer, and it shows great promise for reduced agitation techniques, and some other interesting properties. This developer is even simpler than 510-Pyro, containing only pyro, glycin and TEA. Stain is very high, fog is very low, sharpness and grain are excellent, film speed is good, and the curve is interesting. Glycin's signature is an upswept curve, while pyro tends to shoulder and compress highlights, but the combination produces a very long, slightly upswept curve (with TMY), that might prove to have useful/unique properties for printing with VC papers. Hutchings claimed in The Book of Pyro that both phenidone and ascorbic acid can cause a loss of sharpness in pyro developers. I don't necessarily believe that to be true, but when the opportunity arises to reduce the number of constituents in a formula without adversely affecting its performance, I feel compelled to investigate. The pyro/glycin pair suggests some intriguing possibilities, but hasn't been used historically for logistical reasons that TEA seems to address very well. I have not optimized a pyro-glycin formula, but the one I'm testing is:

PGT

Pyro 10g

Glycin 2.5g

TEA 100ml

The most important formula variable I'm testing is the amount of glycin, or the glycinyro ratio. The above ratio produces a very active developer, similar to 510-Pyro. TEA and glycin have both been linked to fine grain, and this developer seems to live up to that expectation. I am in the very early stages of testing this developer, and I will post more specific data, and sample images when I have them. I'm also testing a catechol version exactly like the developer above, except substituting catechol for the pyro. This developer needs a second alkali solution to bump the pH up into catechol's favored range, and is used much like Hypercat. More to come.

Jay

Jay

 

[Helen B]

Some of Barry Thornton's formulas apparently contain glycin, but since they are proprietary there is no way to know exactly which ones, and how much, or what glycin is in combination with. However, I am fairly certain that one of them contains both phenidone and glycin with pyrocatechin.
...
Sandy

Sandy,

Although Barry didn't reveal the formulae, he did publish information on which developing agents were in which developers:

Exactol: glycin, phenidone, catechol
Exactol Lux: ascorbate, phenidone, catechol
DiLuxol Vitesse: phenidone, metol, ascorbic acid
DiXactol Ultra: glycin, phenidone, catechol
DiXactol: glycin, catechol

He also stated that DiXactol evolved from Windisch catechol by first modifying the B soln. then adding glycin to the A soln, then DiXactol Ultra evolved from that by the addition of a small amount of phenidone. I'm not giving any secrets away here - he published this in his article for PT.

Best,
Helen

 

[sanking]

Hi Helene,

Very interesting. I had not seen this information before.

Thanks,

Sandy

Sandy,

Although Barry didn't reveal the formulae, he did publish information on which developing agents were in which developers:

Exactol: glycin, phenidone, catechol
Exactol Lux: ascorbate, phenidone, catechol
DiLuxol Vitesse: phenidone, metol, ascorbic acid
DiXactol Ultra: glycin, phenidone, catechol
DiXactol: glycin, catechol

Best,
Helen

 

[Dracotype]

Very good contrast on both the print(?) and negative. You have piqued my interest. When I run out of FG7 I might try mixing some of this up. And hopefully by then you will have perfected it. By the way, would this developer be good for alt process negatives?

Drew