Further Development Times and Fine-Tuning For Argyrotypes
Following further recent experiments with Agryotype, and from reading John Blakemore, I’ve been revisiting my developing times for FP4+ with Pyrocat HD 2:2:100. This has firstly allowed me to iron out processing errors I’ve been making lately. My original tests from last year had N at 10’30 and N-1 at 8’05 (a time reduction of 23%). It’s also reminded me to not be lazy with my metering, and to annotate the zonal placements when I make an exposure.
For some reason lately (reading from the wrong page of my notes / not properly updating my phone’s timer app) I’ve been processing at N = 12’, which represents virtually an N+1 overdevelopment, about 15% above N (in the ballpark that John Blakemore has for stepped expansions and contractions).
This is fine if I’m scanning my film but not great if I then want to make argyrotypes with highlight contrast, and is I think one (!) reason why I only managed one successful argyrotype from my last printing session: the white Clematis produced very little detail in the highlights at all (the other errors were because of overeagerness – I exposed the paper before it had sufficiently dried so too much subsequently washed off – I note that Mike Ware recommends drying for 1-2 hours at 20ºC; I had good results in warmer spring conditions with drying for 30mins at 28ºC room temperature, but no shorter than that). This sadly means I’ll have to wait another year to reshoot the white Clematis flower to attempt another argyrotype, while I can still enjoy the scanned version – I think I’d prefer to use a fresh negative than attempt to dodge a contact-print in progress.
Reading Blakemore also means that I’ve been reassessing my developing times. I’m happy with N, N-1, and N-2, but N+1 has now been reassessed given the white Clematis failure. So I’m now going to put N+1 and N+2 at 116% and 132% above N. These times are for developing at 21ºC. I add 9% for every 1ºC above this if I’m developing in warmer conditions.
What I’m also planning to test next is how Argyrotype reacts to expansions and contractions in developing, and how to read these with the zone system. I’m currently working with expansions and contractions as per silver gelatin defaults (using zone VII as the cut off point), and not as per Pt/Pd (I’m not convinced from my tests so far that Argyrotype can approach the tonal subtlety of Pt/Pd in the highlights, but have yet to work with a negative that really tests this).
(So my assumption is that this is more realistic than Platinum/Palladium according to some notes I have, for which expansions and contractions work as follows:
N-1 = zones 2-10, 8 stops
N = zones 2-9, 7 stops
N+1 = zones 2-8, 5.6 stops,
N+1.5 = zones 2-7.5, 4.2 stops )