DIY ILFOCHROME CHEMISTRY (Page 2)
and eventually leads to the formation of diachronic fog.If too much solvent is added a point is reached where its action starts to reduce the paper’s maximum black (due to the excess silver solvent dissolved in the developer eating away at the unexposed silver halide)
Between these two points, however, it is possible to make a series of developers giving scale differences from higher, through normal, to lower contrast and in a repeatable manner. For the creative printer this constitutes a subtle but very valuable additional set of controls.
The Basic Alternative Developer
Since this was an Ilford product I started out by trying the standard Ilford PQ Universal developer at my normal dilution of! 9 and this has worked fine in the final formula as indicated below. Most other print developers will probably be OK as well.The Silver SolventA
5% solution of Hypo, which I had on hand, was found to work very well as the silver solvent, though other more expensive chemicals like potassium thiocyanate at different percentages would probably give similar results. For some purposes a strong solution of salt, a mild silver solvent, may well give interesting results with extended development and a dilute solution of the llfoebrome fix would probably also work -though I haven’t tried it. Plenty of room to experiment here.It should be emphasised that changes to any commercial chemistry may upset the manufacturer’s recommended processing times and or colour balance aim points so we need to run our own recalibration tests to establish new optimum speed and developer times.
After many tests I arrived at three solutions I was happy with, that give slightly different effects. Since changes are only made to the first developer I found I could develop different batches
of material in different formulations, rather like changing
paper grades. This does not affect the rest of the process which is standard. One dilution compared very well with the manufacturer’s own developer and that is a formulation I now use a lot.
Basic Alternative Developer One
Ilford FF Contrast stock l00mI
Water 900m1
Add 26ml of 5% Hypo solution
Discard after use.For optimum results I extend the developing time to 4 minutes at 24°C. The rest of the process uses the standard manufacturer’s chemistry and timing.
Silver Solvent VariationsOther solvent percentages I have found useful for the sort of work 1 do are !3ml per litre for slightly higher contrast and a shift towards blue (which is sometimes useful to improve the printing of slides taken in tungsten light).
A higher strength, up to 50m1 per litre, suits some subjects.
Variable Scaled PrintsIf we want normal scale prints with Dye Bleach materials we need to maintain a good maximum black and keep fog levels down. In cases where we don’t want a normal print (such as for high key subjects or abstract work) we cmi get away with a much lower maximum density. In these situations the DIY developer gives us the possibility of making our own special off-scale papers simply by increasing or decreasing the silver solvent in tandem with time and filter changes.
Calibrating the Developing TimeThe developing time for our new normal leveloper may have to be adjusted to get a maximum black whilst retaining fine ~iighlight detail. The correct exposure to make the best use of this material will ~lways be the minimum that gives a good lull black. Exposures above this level eventually start to block up fine detail and ~educe the sharpness potential of the print.