Jarinb
Allowing Ads
- Joined
- Aug 23, 2009
- Messages
- 3
- Format
- 4x5 Format
Hello all:
I've lately been messing around with making my own pyrocat formulations, both with and without a bit of Glycin, and a partial stand method. So far, generally, I am seemingly not achieving the level of staining that I was with proprietary chemistry like DiXactol or Prescysol EF. I used to shoot Delta films, but have gone the other way, and am now using Efke100.
My last tested formula is for one liter of working solution is:
.45g pyrocatechin
.75g sodium sulfite
12g sodium carbonate
.12g glycin
I mix from dry raw chemicals before each session. As you can see, there is very little sulfite; I also use a water rinse instead of a stop bath, and fresh batches of TF-3 fixer, and I reduce the sulfite there too - to 1/3 or 1/6th of the published amount.
One thing I have noticed is that the greatest staining had occurred with my Delta 3200 negs and prescysol - but these negs also had the longest developing time: 20 minutes or more and they are completely brown.
I am after high apparent sharpness, but the priority is nice separated tonality, subjective dimensionality (hence changing to cubic grain) with semi-compensated highlights that hold. I am now shooting 4x5 and developing in an Arkay tank with film hangers.
Anyway, I was going to reduce the glycin again (to .06/L), the catechin to .4/L or less, wait 4 minutes between agitations (instead of 2 or 3), and try a longer development time to increase the stain. Are there any other suggestions? I started this foray using only catechin (but in 35mm), and the edge effects were far too extreme - quite etched with thick borders to all the edges. I am really going for the best tonality and across-the-scale information for grade 3 printing with medium to high contrast subjects.
Thanks!
I've lately been messing around with making my own pyrocat formulations, both with and without a bit of Glycin, and a partial stand method. So far, generally, I am seemingly not achieving the level of staining that I was with proprietary chemistry like DiXactol or Prescysol EF. I used to shoot Delta films, but have gone the other way, and am now using Efke100.
My last tested formula is for one liter of working solution is:
.45g pyrocatechin
.75g sodium sulfite
12g sodium carbonate
.12g glycin
I mix from dry raw chemicals before each session. As you can see, there is very little sulfite; I also use a water rinse instead of a stop bath, and fresh batches of TF-3 fixer, and I reduce the sulfite there too - to 1/3 or 1/6th of the published amount.
One thing I have noticed is that the greatest staining had occurred with my Delta 3200 negs and prescysol - but these negs also had the longest developing time: 20 minutes or more and they are completely brown.
I am after high apparent sharpness, but the priority is nice separated tonality, subjective dimensionality (hence changing to cubic grain) with semi-compensated highlights that hold. I am now shooting 4x5 and developing in an Arkay tank with film hangers.
Anyway, I was going to reduce the glycin again (to .06/L), the catechin to .4/L or less, wait 4 minutes between agitations (instead of 2 or 3), and try a longer development time to increase the stain. Are there any other suggestions? I started this foray using only catechin (but in 35mm), and the edge effects were far too extreme - quite etched with thick borders to all the edges. I am really going for the best tonality and across-the-scale information for grade 3 printing with medium to high contrast subjects.
Thanks!
