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Bleach, Bleach, and Monobath

When the contrast range of the subject is extremely high (for instance a church interior with dark shadows and an exterior window or view, or perhaps a landscape with deeply shaded forest foreground and sunlit or sky background) even 2 bath with curtailed times down to 2 minutes in each bath may not cope. Even if the highlights are burned in during enlarging they show only an ugly featureless grey because the highlights have been pushed up on the shoulder of the film’s characteristic curve, and there isn’t any separation between the tones avail- able to print. One solution is to continue to expose the film for the shadows in the usual way, then before development, to bleach the film in a highly dilute ferricyanide bleach.

This very gently and slowly ’cuts down’ the latent image in the film starting with heavy highlight densities. This is the opposite of the effect when it is used in printing, as mentioned in my book ’Elements’, when it prevents shadows from going solid. It is a very tolerant process, and while times and dilutions will be amended with practice, it takes quite wide variations for significant differences in result. So you can safely start from the point I mention below, but, as always before use on a vital negative, experiment with unimportant ones. You can mix your own bleach with 10 grams of potassium ferricyanide and 3.3 grams of potassium bromide to 1 litre of water, or you can use the bleach that comes with Paterson’s, Fotospeed, (or similar) sepia toner also diluted to 1 litre initially. Further dilute 10mls of this to 1 litre. Use this at the same temperature as your film developer. Presoak you film in it in the developing tank for about 3 minutes, then discard the bleach. Rinse the tank out thoroughly with clean water, then develop (using 2 Bath it you wish), stop, and fix in the normal way. You will find that the highlights have been reduced so that they come down off the shoulder and print normally without burning in, while the midtones are barely affected, and the shadow density and contrast remain unaffected. Usually, giving a half stop extra exposure initially will restore midtone snap, and put extra body into the shadows. Varying either time of immersion in the bleach or its dilution will control the amount of highlight cutback and the degree of influence on the midtones. The only trouble with the pre-bleach system it that, tolerant as it is, if you over or under do it, you can’t recover the neg. and start again. Also, until the negative has been developed, you don’t actually know how contrasty it is. Nor will the system deal with a negative that has already been developed and has been found to have too high a contrast to print well. Well, thanks to a most helpful correspondent, Michael Grayson Healey, I have found a method that does all these things, gives impeccable sharpness and fine grain, enables the curve of the negatives to be tailored to fit the paper for sparkling prints encompassing virtually any subject brightness range. It does all these things by inspection in ordinary room lighting after normal development (even years after). Here’s how it works.

Monobath developers are developers with incorporated fixer. The powerful developer works so quickly that it builds up density before the fixer can work properly. It produces very fine grain, excellent sharpness through edge effects, and outstanding evenness. Unfortunately, for ordinary use, the weak shadow areas are fixed out before the developer can work and are largely lost. We can make use of this to change the characteristic curve to help us contract the overall contrast of the negative to print easily yet to steepen the curves in shadow and highlight to counteract the toe and shoulder of the paper so that there is sparkle in the highlights and depth in the shadows unobtainable in any other way. Develop the film, even those of high contrast subjects, for the normal time, stop, fix and wash in the normal way. You can use old negs. too, Using water 400ml; pot. ferri. 11g; pot. brom. 12.5g; water to 500ml, bleach away the image completely (Note: not Farmer’s reducer). Discard the bleach and wash all traces of it from the film. Now, in room light by inspection, partially develop the image using a weak high definition developer. A good one is Water 800ml; Metol 0.5g; Sodium Sulphite 2.5g; Sodium Carbonate 2.5g; Water to 1 litre. You can also try double or triple dilution ordinary developers like Rodinal. Pull out the negative when the shadows seem to have developed, but the midtones are still flat. Water rinse the negative then put it in the Monobath developer. Between 30 seconds and a minute later this development will be complete. The Monobath’s tendency to cut the shadows can no longer work since they have already been developed by the first developer. The Monobath treats the mid tones as its shadows and therefore gives the highlights proportionally more density. Thus the contrast gradient in the midtones is shallower than both shadows or highlights. After the Monobath, stop, fix, wash and dry. Everything is done in room lighting. If the result is not quite what you wanted, simply rebleach and start again varying the first developer time or strength a little, until you have exactly the result you wish! For the Monobath you can use Tetenal’s pre-packaged Monotenal, or mix your own. Try Sodium Sulphite 6g; Hydroquinone 3g; Metol 0.125g; Sodium Thiosulphate 40g; Sodium Hydroxide 5 g; Water to 250ml.. It is well worth experimenting with this technique. There’s little to lose!

 


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