Is glycin a staining developing agent?

[pgomena]

I've used TFX-2 developer a few times, and I have a question regarding this or any other film developer containing glycin: Is glycin a stain-producing agent like pyrogallol or catechol?

My negs in TFX-2 appear to have a bit of a warm cast to them, but I can't tell with my naked eye if this is a staining effect.

If it is not a staining developing agent, what is the magical effect of glycin that allows it to produce such finely detailed highlights that don't want to block up? Is it simply an excellent compensating agent?

Peter Gomena

 

[Helen B]

This may be of interest: from L P Clerc's Photography Theory and Practice, 1971 edition revised by R. E. Jacobson, Vol 4, Monochrome Processing.

"573. ... The following table (Lumière and Seyewetz, 1928) shows the colour of the secondary image obtained in various developers, its relative intensity and the concentration of sulphite necessary to prevent its formation.

Developer -- colour -- relative intensity -- sulphite g/litre

Pyro -- yellow-orange -- 10 -- 11
Catechol -- black -- 10 -- 6
Hydroquinone -- yellow-brown -- 10 -- 2
Chlorhydroquinone -- yellow-brown -- 10 -- 2
Amidol -- reddish-brown -- 8 -- 2
p-Aminophenol -- brownish-black -- 3 -- 2
Metol -- brownish-black -- 2 -- 1
PPD -- Grey -- 1 -- 0
Glycin -- None."


Best,
Helen

 

[pgomena]

Thanks, Helen.

I looked up TFX-2's ingredients on the Photographer's Formulary website and it contains metol as well as glycin. From the chart you provided, it appears that metol is likely responsible for the warm color in the negs.

So, what then are the properties of glycin alone or in combination with metol that are desireable in a developer? I'm not a chemist, but I see good things happening in my negatives and am curious.

Peter Gomena

 

[jim appleyard]

Here's a bit on glycin and other devving agents:
http://unblinkingeye.com/Articles/Developers/developers.html

Lots of other good info on that site as well.

 

[pgomena]

Thanks, Jim, that's just the ticket!

Peter Gomena