THE
CIBACHROME PHENOMINOM
By Norman E. Davies (Area 3)
On remembering
that I had a stock of Cibachrome paper some of which must be at least
15 years old (the latest dated June 1988) and kept mostly at room
temperature, the possibility that it would give a picture at all
seemed remote. However inspired by articles by Bill Broadhurst Area 4
(Issue No. 53) and Ed. Herson Area 11 (Issue No. 65) and now in
retirement from the day job I decided to give it a go.
The first thing
to investigate was the chemicals I had available. Some partly used P-12 developer, part 1B of which looked very
unhealthy and was discarded. Some
partly used P-30 developer, part 1B which again was discarded.
1 Litre of P-30P developer, 5 Litres of P-12 bleach, 1 Litre
P-30 bleach, 2 Litres P-30P bleach, 7 Litres of P-30P fixer.
Having
discarded the liquid developer, the article by Ron Croad (Issue No.
58) gave an alternative which he had found satisfactory and 2 Litres
were weighed and mixed. The
5 litres of P-12 was mixed at process temperature and assumed usable.
The full amount of P-12 bleach was mixed as it could not be
sub-divided. 2 Litres of
the fixer was prepared.
Having
demonstrated some years ago at an Area 3 meeting my own version of a
deep tank processor for colour negative printing after having
unsatisfactory results working with a colour drum, I decided to try a
version for colour reversal printing.
This consists
of a plastic storage container fitted with a fabricated plastic top in
which fit four 1½ litre circular containers with snap-on lids. The first of these I purchased at Woolworths made by Rosedale
Mouldings Ltd., Bedwas, Gwent and lately three similar from T. J.
Hughes. In the local
market I found a 100w aquarium heater with an external control
manufactured in the U.K. for Thomas`s, Bately, W. Yorks, WF17 9UL
which when full out gave a water jacket temperature of 30 degrees and
easily adjusted to the 24 degree process temperature.
Paper holders consist of a 1½ litre plastic bottles with the
bottom cut off which just takes a 10 x 8 print emulsion side in.
Test strips can be processed using a film clip on a plastic
coated wire. A sketch of
the equipment is appended.
The first
container has the developer followed by a 1% acetic acid stop bath.
The third container holds holds the bleach followed by a water
rinse in an external container to avoid excess carry-over into the
fourth container holding the fixer.
Washing is carried out in another external container placed in
a sink (in my case the bedroom vanity unit) with a flexible tube
placed in the neck of the bottle paper holder.
Exposure, development and stop bath are carried on using a
safety light but after initial immersion in the bleach the rest of the
operation can be carried on in room light.
Luminous strips in front of the containers help in locating the
paper holder.
Now came
the moment of truth.
The Durst
enlarger was adjusted to 10 x 8 with my prized tranny of Ashness
Bridge. The filtration of
40Y + 05c was dialed in from the long ago opened pack (I forgot to
adjust for Durst values) and set the exposure to a guessed 6 secs @
f11. A check on the P12
process timing at 24 degree C gave 2 mins. development (Ron said 3
min, but assumed no one could possibly have paper from prehistoric
times). 4 mins. bleach, 3
mins. fix and 3 mins. wash. Used
with a 30 second stop after development and on removal from solutions
the holder is tapped on the top of the container to drain.
A full
sheet of paper was placed in the masking frame (to hell with the
expense), exposed and placed in the paper holder.
The advantage of the deep tank is that the whole exposed paper
is immediately immersed and this avoids possible areas of under
development or uneven bleaching.
Stop and bleach, was there a picture?
Yes! At the end of
the bleaching stage through the plastic of the bottle a picture was
visible. A quick twirl in the rinse and into the fixer. The three
minutes wash seemed an age but on removal from the holder there it was
in all its glory.
After the
first elation (similar to that feeling when you draw your first roll
of processed trannies from the spool) comes the drying and critical
assessment. The unexposed
edges were blue not black (paper deterioration).
Slight magenta cast (paper or filtration ? Increase yellow
& cyan). Slight over
exposure. The fourth
print at 55y + 10c with 6 seconds @ f11 was assumed to be the best
that could be obtained with this paper.
All the remaining paper gave acceptable prints, the 1988 paper
having black unexposed edges some of which has still to be used.
Exposure was set on the magenta memory of a Durst CM 300 and
used successfully on all remaining enlargements.
When the
containers are filled with solution mixing, 2 litres leaves ½ litre
for replenishment. No
recommendations are given in the Cibachrome manuals but suggest with
their table top processor that 30 - 10 x 8 can be printed in 2 litres
of solutions. Assuming you could get 32 I have adopted for the following
replenishment rates.
First 8 as
mixed, Second 8 add 80ml, Third 8 add 165ml and fourth 8 add 255ml.
When replenishing remove more than the amount of top up, add
the required amount and bring back to 1½ litre level. Agitation is by
twisting the bottle neck, 15 seconds initially in each solution and
after each minute a further 15 seconds.
Care should be taken to avoid surface damage on removing the
print from the holder.
According
to my notes 50 - 10 x 8 and 25 - 7 x 5 prints were produced in the
months between February and May 1995 using 5 litres of solution.
I found that 8 prints plus some test strips for colour balance
could be completed in say a three hour session which from my
experience would be possible to attain with a colour drum.
No failures could be attributed to the processor which was left
switched on for long periods between sessions with the caps in place.
When I order some more chemicals from Ron I should be able to
use up the remaining paper and try some that is say only six months
out of date. But that
will wait as I must try in the processor those R14 chemicals and paper
I bought some time ago.
Anyone
want to buy a colour drum?
Further
Notes on building the processor "High-impact Polystyrene can be
obtained from your local model shop (Roy Salmons at Photoworld will be
pleased I`m sure to supply at competitive rates) and bonded with
either tube or liquid cement. It
is supplied in sheets approx. 14" x 10" in various
thicknesses and two pieces at 60 thou thick spliced together will be
required to form the top plate. A
third piece will be required for the stiffening ribs and the perimeter
spillage kerbs. 20 thou thickness is used for the kerbs around the solution
containers as thicker material is difficult to form. The material can be cut by scribing with a model knife and
breaking on the line. Circles
for the containers can be scribed with a compass and broken out with
right angle cuts across the diameter.
The fit of the solution containers should be as tight as
possible to prevent excess water spillage into the water jacket.
I have not found it necessary to provide wa
ter agitation at the process temperature with the heater positioned
between the containers."