Staining negative developer
Suitable for tank and tray development.
Rotation development is possible, but in direct comparison the sharpness performance is significantly lower.
For machine development we recommend the TAS film processor from Heiland Electronic.
With one exception, pre-watering is not necessary. During the development of Delta 400, a strong foaming occurs after a few minutes, which can lead to development errors if the can is tightly filled. After pre-watering for two to three minutes, the problem no longer occurs.
Developer and alkali are diluted 1+1+100 with water immediately before development. With such a high dilution, the water quality can have an effect on the film speed, so we recommend preparing the working solution with demineralised water. If tap water is used, the film speed may deviate by 1 DIN from the values given in the table, both upwards and downwards.
In contrast to the well-known stain developers based on pyrogallol, auto-oxidation starts much later. This is advantageous for N+ developments according to the zone system, a “collapse” of the developer during long development times is not to be feared.
As with pyrogallol, a dye forms in proportion to the silver density. The “Tanol stain” is less noticeable to the eye than the “Pyro stain”, but just as effective. The dye accumulates between the silver grains and reduces the impression of graininess that is almost inevitable with sharpness developers.
When using fixed-gradation papers, the Tanol stain has only little influence on the highlight contrast if the recommended times are observed. With gradation change papers, the stain acts like an additional soft filter in the high densities.
This developer is particularly interesting for large formats when negatives are to be usable for the conventional silver process and the “alternative processes” such as platinum printing, Cyanotype, etc. The stain has little effect on the light contrast of early contact processes. The contact processes from the early days of photography require high light densities with straight curves. The required contrast range is between 1.7 and 2.0 logD. Exposure is with daylight or with UV light sources. Because the stain blocks UV light, printing can be done directly from the original negative.
Shelf life of concentrates: A one year or longer, B unlimited.
2x100ml makes 20 litres of working solution – capacity 40 films.
Finol Datasheet EN