A
number of members already use, and process, black and white and colour
negative films. If they are
anything like the members of our local club, however slides are by far
the most popular (although our local lot seem reluctant to process their
own - I`ve tried to tell the the error of their ways but Kodachrome
rules!).
If
anyone is wondering whether to give monochrome a try but doesn`t want to
mix up several solutions, nor spend a lot of time and effort on the
first trial run, why not use a monobath?
These were all the rage at one time but seem to have fallen from
grace of late. I`ve dug out
a formula from the 1976 edition of the British Journal of Photography
Annual which is listed below. The
bath gives no alteration in film speed and is adjusted to produce
negatives of average contrast. The
contrast can be altered to suit individual taste or working conditions
by varying the sodium thiosulphate content.
Between 75G and 125g/litre will give continuously graded
softening of contrast; softer results than obtained at 125g/litre are
unlikely to be required. For still higher contrast increase the hydroquinone to 17g.
Sodium
Sulphite anhydrous 50g.
Hydroquinone
12g.
Phenidone
1g.
Sodium Hydroxide
10g.
Sodium Thiosulphate
90g.
Water to
1 Litre.
To
quote the details on mixing up - a little Calgon may be used. The bath
may be divided into two stock solutions:
a) developing agents and sulphite;
b) sodium thiosulphate. On
mixing add 1 pellet of sodium hydroxide per working 30ml.
This is quite accurate enough, and may be used whenever making up
the bath.
Slow
and medium speed film will process in 4 minutes but six minutes @ 20C is
the safe time for all films. Agitate continuously for the first half minute after pouring
the solution into the tank, then at each minute about three to five
inversions. Then wash for
between five and twenty minutes. The
bath will process up to twelve films per litre, and should be kept in
full bottles until deeply discoloured.
The
same book gives details of reversal processing of normal black and white
negative film, based on the use of May & Baker `Qualitol`, but as
this is not available any more, to my knowledge, it is of academic
interest only. There used
to be many formulae for such a process but one doesn`t see them these
days. If anyone has a
particular favourite that works well then please share it.
As users
of Agfa DiaDirect Monochrome slides will confirm, there is something
still worth having in a black and white slide.
They have a beauty all of their own.