Pyro and VC Printing
Is the Pyro neg. flexible enough to be used for both long scale processes (eg Platinum) and for conventional printing using variable contrast papers ?
Compare and contrast the following 2 statements.
'The benefits of this [PMK dev] I have found to be greatly overstated. In particular, its variable colour of stain with differing emulsions gives variable results with VC paper. The yellow-green stain which is most marked on HP5Plus, FP4 and TRI-X, gives distorted and often unpleasant tones on these papers, though occasionally it can be made to work. It does work well on graded papers though.'
Barry Thornton, The A-Z of Ilford Delta 100, Professional Photographer, March 1996
Barry then lists the following formula as providing superior sharpness, better and stronger staining and non-actinic brown stain (neutral effect on VC papers) compared with PMK..
It is also very economical and long-lasting.
The formula is:
Bath A conc.
Pyrocatechin ...................... 10 g.
Sodium sulphite ..........2 g.
Potassium bromide ....0.5 g.
Water to 100ml.
Bath B conc.
Potassium hydroxide ....10 g.
Potassium bromide ......0.5 g.
Water to make 100ml.
Development Sequence
Both are mixed at 1+14 to make separate A and B working solutions.
Time for nearly all films is 4 minutes in each bath at 21 C.
Agitation is once every 30 secs in bath A, once every minute in bath B.
No rinse between baths.
Normal stop and fix after.
(NB: No post fix bathing in alkaline solutions required by PMK.)
Although not intended for Jobo rotational development, I'd be interested to know if anyone has tried this (or a similar formula) with the Jobo system.
Also, it is only a starting point for further refinement.
Note: Rodinal 1+25 is a compensation type developer so theoretically is not for Jobo use but I get great results with it for almost any film in my Jobo system!!
PMK Pyro: UK Supplier
Note for those who have difficulty obtaining chemistry (or time!) to make their own PMK dev. there is a UK source for PMK Pryo:
Photo Chemical Solutions,
7 Stand Rise
Radcliffe
Manchester
M26 1BT
TEL: +44 [0] 161 280 2406
Also check out the usual Bostick & Sullivan (USA) and SilverPrint (UK). Both have web sites of the same name!
(NB: I do not have shares in these business! - they were helpful in the past...)
THANKS
Many thanks to the group for the advice about:
pre-bathing in sodium metaborate
using the A and B PMK baths separately
not using Photoflow (which I never use anyway!)
using EDTA
using the Jobo Expert 3005 drum rather than the 2500 series (damn fiddly in the dark!!)
etc..
My Questions About PMK Pyro In the Jobo ATL-2 system
1 Due to Pyro staining is it better to keep a set of spirals/tank separate from all other processes eg, Rodinal, E-6, C-41 etc...?
2 Which rotation speed is best for Pyro?
3 Is the agitation method on the ATL-2 of bi-directional rotation plus up and down movement better than simple rotation ?
4 Can wash cycles at 20 C in a plumbed-in system be used at any stage ?
5 How do you get the spent A+B alkali Pyro mix back into the sequence (or is this a silly question!) ?
6 Is it better to use the higher temperature (and thus shorter times to minimise aerial oxidation ?
(NB: Oxygen could also be excluded by filling the drum almost completely full of the A+B mix but for a 3005 drum could be an expensive way of eliminating air!!)
7. Should the ISO be halved for Pyro developer (eg HP5+ at 200ISO; FP4+ at 50 ISO) ?
Yet Another PMK Reference
See Norman Wilson (I had to get another Irishman in somewhere!) in
'Pyro Technics', Darkroom User, Spring 1995
(100410-1561@compuserve.co.uk)
Yet Another A/B Formula!
For any T-Max 100 (TMY) sceptics the following formula given by Joe Englander in Ag+, Vol.9 (now published by BJP) might be worth a try:
A
Water (52 C)................ 750 ml.
Metol .......................... 10 g.
Sodium sulphite .............75 g.
Cold water to make ...........1 L.
B
Water (20 C) ................750 ml.
Sodium sulphite ................5 g.
Sodium carbonate ............15 g.
Water to make ..................1 L.
DEV SEQUENCE:
3 mins dev in part A
no rinse
3 mins in part B
(Jobo @ 50 rpm with same times)
water rinse
fresh fixer
wash normally
The initial ISO is a true 100 ISO.
Results: overall contrast is normal (NOT flat as with many A/B systems) yet mid range contrast gives good separation. Highlights are smooth/full range. Good A/B-style shadows. Could be useful for alt Proc.
Hopefully this is helpful to someone and I have not been too long-winded an Irishman !...
God Bless
Michael.