|Ansco Printon & Plenacolor ~ Researched by Michael Talbert|
to this web page:
I am indebted to Michael Talbert for the following information.
Also, see his research on early Kodak colour print materials.
Also, see his research on early Gevaert colour materials.
Also, see his research on early Agfa colour materials.
|Ansco Color Printon
Handling Printon in the darkroom
Exposure of Ansco Color Printon
Processing Printon with the 'Ansco Color Printon Developing Outfit'
Ansco Color Printon processing procedure dating from 1948
Anscochrome Type Printon processing procedure dating from 1960
1968 Processing Sequence giving times for 68°F and 75°F.
Ansco Color Compensating Filters for use with Ansco Printon
Exposure factors for Ansco Color Compensating Filters
End of Printon in 1973
|Ansco Plenacolor Negative Film
Possible processing procedure for Ansco Plenacolor film
Processing Steps for Ansco Plenacolor Negative Film
Printing Ansco Plenacolor Negatives
Ansco Color Printon was a reversible opaque colour print material for making colour prints directly from colour transparencies without the use of an internegative. It was first made in 1943 by Ansco, Binghamton, New York, USA for industry and the US military, but by 1945 it was sold directly to professional photographers and amateur photographers.
A detailed history of Ansco
can be read on the Wikipedia webpage here.
It was the first colour print
material in the world of the integral tri-pack type where the
user could expose and process his own colour prints. The emulsions
were coated onto a white opaque colour film type of material
with an acetate base, not a paper base, similar to a thick sheet
film. It was slightly thicker than the Kodak single weight black
and white printing paper available in WW II, and was much like
the material used by Eastman Kodak for making their Minicolor
prints from Kodachrome transparencies. From the base upwards
the first emulsion was the red sensitive layer containing the
cyan coupler which gave the cyan dye image. On top of this layer
was coated a green sensitive emulsion containing the magenta
coupler. This produced the green dye image. Because the red emulsion
and the green emulsion were both sensitive to blue light, a yellow
filter was inserted between the green emulsion layer and the
top layer, sensitive to blue light and contained the yellow coupler,
producing a yellow image.
As Printon was a reversal material, the first solution in the processing sequence, a black and white developer, produced a black and white negative image. Any photographic material developed to a negative image also contains an undeveloped, and unexposed, positive image, the exact reversal of the black and white negative image. This remained undeveloped in the black and white developer because it was unexposed. Printon makes use of this fact by exposing the undeveloped positive image to light, (because it was unexposed), and then developing this image in a colour developer which reacts with the colour couplers to produce a coloured positive image, the exact opposite of the black and white negative image.
At the end of the colour development step there are a black and white negative image and a colour positive dye image in the Printon. We only want a colour positive dye image, but the Printon contains the developed silver produced in the black and white developer and the colour developer. So the next processing step is the Bleach bath, which converts all the metallic silver into silver halide. The silver halide is made soluble by the following bath, which is the Fixer. Most of the soluble silver halide remains in the Fixing bath, and any left in the Printon is removed in the final wash. The unwanted black and white negative image, because it had been produced in a black and white developer, is unable to generate a coloured image, and is completely removed. The silver is also removed from the positive colour image, produced in the colour developer, to leave the dye image containing cyan, magenta, and yellow dyes, making up the original scene. The final wash removes any chemicals and silver not retained by the Fixing bath, and an Anti-Staining bath completes the processing sequence before drying.
Printon in the darkroom
of Ansco Color Printon
At the time of the introduction of Printon very few photographers would have had any knowledge of making prints from a colour transparency onto an unknown tri-pack material. Some were skilled in making Tri-Chrome Carbro or Kodak Wash-Off Relief prints (later known as Dye Transfer) from colour transparencies, and would have had the necessary skills to recognize colour casts in Printon test prints. But the method of filtering, or removing colour casts, from Printon would have been entirely different to changing the colour balance of these assembly type printing methods. Colour casts on Ansco Printons were removed by the use of colour filters, much the same way as colour negative/positive printing, but with the opposite effect.
Ansco probably had in mind a person doing colour printing for the first time, so their colour printing filters were fairly easy to use. And to help the 'first time' printer expose his first test strip, each label on the packets of Printon carried a starting filtration which could be made up of Ansco filters for a trial test print. Of course, because of the vast range of enlargers, enlarging lamps, and methods of printing, this trial filtration could only be a rough guide, and it was extremely unlikely that the first test print at this filtration would have produced a neutral print. But it was at least a good starting point.
An exposure time recommended for the first trial print was 2, 4, 8 and 16 times the exposure time given to a successful black and white print made on Ansco Brovira contrast grade 2 (possibly Normal grade) paper. Ansco also pointed out that a heat absorbing glass was essential when using Printon, as was a U.V. filter, such as Ansco Color UV-16P. A Kodak Wratten 2A filter was a good substitute. Without the heat absorbing glass in the enlarger, it was possible that some prints would have required a very high cyan filtration to eliminate heavy red casts caused by the lack of the heat absorbing filter.
Printon with the 'Ansco Color Printon Developing Outfit'
Owing to the emulsions of Printon being coated onto a white plastic base material, sheets of Printon could be loaded into groove type film processing hangers where the sheets were slid into grooves which held them securely on all four sides. Clip hangers could also be used where a clip gripped each corner of the sheet.
Color Printon processing procedure dating from 1948
Processing was carried out at any temperature between 65°F and 75°F, but the processing times of the two developers varied by ½ minute (First Developer) and 1 minute (Colour Developer) for each degree F, upwards or downwards. The bleach times were also variable according to the temperature of the solution.
During the 1950s the processing times of Ansco Printon were changed slightly. The two development times were altered and there was a shorter Bleach time.
Type Printon processing procedure dating from 1960
Total time excluding drying: 73 minutes.
Total time excluding drying: 76 minutes 10 seconds (68°F), 64 minutes 40 seconds (75°F)
Color Compensating Filters for use with Ansco Printon
The Yellow filters were coded
as: 23, 24, 25, plus a 26, introduced later.
Early instruction sheets for Printon state that there were just these three yellow filters, but certainly by 1948 there was an additional Yellow 26 filter included in the set.
Ansco Color Compensating filters were fabricated so that any filter of any colour has twice the strength of the preceding one, the Nos. 23, 33, and 43 being the weakest filters in the set. Thus, a Yellow 24 has twice the strength of a Yellow 23, but half the strength of a Yellow 25. A Magenta 36 was equal to eight Magenta 33 filters.
The labels on the packets of
Printon stated a trial filtration, such as: Recommended
filter combination for use with this emulsion: 1 - 23
and 1 - 43.
Colour casts were removed by placing the opposite colour filter to the colour cast in the filter draw. If the test print turned out with a Blue cast, a Yellow filter was placed in the filter draw for the next trial print. The strength of the filter was according to the strength of the colour cast, a heavy colour cast would need a strong filter to bring the colour balance to neutral.
In an article published in the British Journal of Photography Almanac for 1954 on making and processing Agfacolor prints, there is a table giving comparative strengths of Agfacolor printing filters, Kodak Compensating filters, and Ansco Color Compensating filters. The weakest Ansco filters, Nos. 23, 33, and 43 are given as equal strength to a 10 value Agfacolor filter, or a CC05 Kodak filter.
The highest value Ansco filters, Nos. 26 and 36, have an equivalent value of an 80 Agfacolor filter, or a CC40 Kodak filter.
The author of the article wisely states that the table of equivalent filters are probably not identical to those of Agfa . Kodak Colour Printing filters were not in existence in 1954 but the CC range was being used for colour printing. The Agfacolor filters at that time would have been separate glass filters, and although Agfacolor Heads incorporating dial in filters had been in use for about five years; it is fairly certain that the article refers to the glass filter set. The article also states .Ansco Printon correction filters have proved quite satisfactory to eliminate even serious colour casts.
Ansco suggest in their literature
a method of writing filtrations by listing the filters used in
columns equivalent to the Nos. 23, 33, and 43 filters.
Athough this appears to be a very laborious way of writing filtrations, and prone to errors when copying the figures is concerned, it may have been suggested to help beginners in colour printing to become proficient at filtering colour casts and to work in eights of the 26 and 36 filters.
Ansco mention that it was never
necessary to include yellow, magenta, and cyan filters together
in the same filtration, as this only served to increase the exposure
of the print.
This filtration was equal to two 23 Yellow filters and one 33 Magenta filter, as the top row cancelled itself out.
The rear label of an Ansco Printon box dating from 1961.
A starting filtration is suggested of one 10 Magenta filter and one 10 Yellow filter. By the late 1950s the earlier Ansco Color Compensating filters of 23,33,43, series (see above) had been replaced by this more conventional numerical system of filter designation.
factors for Ansco Color Compensating Filters
When removing filters, the exposure time was divided by the appropriate factor. These exposure factors applied to each filter regardless of the colour of the filter.
In practice, as the printer gained experience in colour printing, he often disregarded the factors and worked out the exposure times based on his experience on making previous prints. If a large change in the filtration was necessary, a stepped exposure test strip could be made. Colour reversal print materials generally had much more latitude in their exposure times than negative positive printing papers.
of Printon in 1973
By the early 1970s, Ilfords Cibachrome Print material was making a favourable impression. The total wet processing time of the Cibachrome Print material had been reduced from 47 minutes for the 6 solution P-7A process of 1969 to 16½ minutes wet processing in 1974 using the, then new, P-18 process with only three solutions.
Ansco Plenacolor was a colour negative roll film, publicized by Ansco in 1946 but not marketed until 1949. It featured a positive yellow mask in the dye forming green sensitive and red sensitive layers. Processing was complex, and was only undertaken by Ansco. The negatives may have been printed onto an Ansco colour printing paper suitable for masked colour negatives or Ansco may have chosen the technically simpler option (avoiding the need for their own research) of printing onto Kodacolor Type II or Type III paper. Plenacolor negatives would have looked yellow, where Kodacolor negatives would have looked orange, as Kodak used a reddish coupler as well as a yellow one. Hence, Kodacolor paper wouldn't have been entirely compatible but would have been closer than a paper used for unmasked negatives, such as Agfacolor CNIII.
In Ektacolor/Kodacolor negatives, the mask was generated by a yellow coupler formed in colour development. Where the layer is exposed, the mask loses its yellow colour and the magenta dye generated from the exposed areas absorbs blue in place of the yellow coupler. The mask was a yellow positive of the negative image.
The Plenacolor mask was put into the film after the camera image was formed by the colour developer, and then the dye was bleached out of the negative areas of the camera image's exposed areas, to leave a positive mask.
processing procedure for Ansco Plenacolor film
This method of increasing the speed of photographic film is known as Latensification. It works by increasing the density of the latent image already formed by the camera exposure. Any developer, black and white or colour, then forms a very slight extra density of developed silver on top of the image made by the camera, thus effectively increasing the density of the original exposure made by the camera. At best, Latensification would increase the film speed by around a stop, i.e. double the original speed of the film.
The film was then placed into a colour developer, which developed the three dye forming layers to produce yellow, magenta and cyan images in their appropriate layers. This step was similar to the colour development step in Kodak's C-22 or C-41 colour negative processes.
The next step was a Blue Light exposure. The emulsion side only was exposed to blue light to form a latent image in the blue sensitive layer, which already carried a developed, but not bleached or fixed, image formed by the previous step.
Black and white development followed the Blue Light exposure step. As the blue sensitive layer of the film was the top layer, i.e. furthest from the actual base of the film and had beneath it a yellow filter, the blue light exposure could not affect the middle green sensitive, or the bottom red sensitive, layers. The black and white developer then only developed the exposed silver image formed by the blue light exposure.
In the blue sensitive layer, after the black and white development step, there was a colour developed negative yellow dye image, and a black and white developed image. The black and white developer couldn't form any coloured dye image. In fact, part of the image was a black and white positive, caused by its exposure during the "Blue Light" exposure step. This 'part image' was not exposed in the camera and thus was not affected by the initial colour development step.
All layers in the film were then dyed yellow in a yellow azo dye bath.
The film was then treated in a Silver Dye Bleach bath. The Silver Dye Bleach bath removed any dye from wherever developed silver was present, i.e. in the exposed areas of the film, but left the dye in the unexposed areas. All three layers had developed silver in them, formed by the colour development step producing a negative coloured dye image. The Blue sensitive layer had the colour dye negative image formed by the camera exposure plus a positive black and white silver image formed by the blue light exposure. The Silver Dye Bleach removed part of the yellow dye from the red and green sensitive layers where developed silver had formed the colour negative image, and in the blue sensitive layer the Silver Dye Bleach removed the yellow dye from the colour negative image plus it also removed the dye from the exposed and developed black and white positive image. The Silver Dye Bleach only removed the yellow azo dye, and not any of the cyan, yellow and magenta dyes generated by the colour development step.
The film was then bleached and fixed to remove the silver images, leaving the negative dye images in the three layers. At this stage the film now had a yellow positive dye mask in the green and red sensitive layers, but no mask (i.e. yellow dye) in the blue sensitive layer. The black and white positive image and any other exposed and developed silver was removed in the bleach and fixing steps.
Ansco Plenacolor Negatives
The following is taken from issues of Popular Photography magazine, June 1949, December 1948, and September 1951.
The mask works in a similar way to Kodaks Ektacolor film masking. In Plenacolor, the full amount of Magenta dye, as generated by the colour development step, is present in the highlight areas of the negative, dark areas of the negative where it has been fully exposed. This is where the Silver Dye Bleach has removed most of the yellow dye.
The least amount of Magenta dye is in the shadow areas, light areas on the negative where it has been least exposed. This is where the Silver Dye Bleach has not removed the yellow dye.
The full amount of yellow dye in the unexposed areas absorbs the same amount of blue light as the full amount of magenta dye in the fully exposed areas (see Note 2, above).
In June 1949, Ansco Color Laboratories at Binghampton, N.Y. were processing and printing Plenacolor films on equipment installed by Pavelle Color Incorporated. The sizes of Plenacolor prints were similar to Eastman Kodaks Kodacolor prints. All prints were made on 3½ inch wide rolls of paper, the length of the print being proportional to the length of the negative.
(Authors Note: It looks as if the printing paper, if made by Ansco, was only used internally by Ansco for prints from Plenacolor negatives, much like Kodacolor paper in those days. Maybe it was Kodacolor paper they were using, as I doubt if Pavelle were making a colour printing paper in 1949. Kodacolor paper is a possibility, as there were no back markings on Kodacolor paper then, (e.g. "A KODAK ® PAPER"), only a date stamp, put on after the print had been made. And Kodacolor paper would, probably, have had an increased sensitivity to blue light for printing from masked negatives.)
Plenacolor films were produced in 120 and 620 roll film sizes, and a 6 exposure film, 120 or 620, cost $1.91 including the processing to a negative, but not printing. Prints cost 36 US cents each. (It is not clear whether these prices included the Federal Tax.)
In December 1948 Gamermans for Cameramen of Baltimore were advertising Plenacolor and Kodacolor 120 and 620 roll films for sale for $1.92 per roll.
In September 1951 Plenacolor roll film cost $1.45 per roll of 120 or 620 film including F.E.T. F.E.T. may have been the Federal Tax at that time.
It was reported in the British
Journal Photographic Almanac of 1953 that:
The year, in the above BJPA statement, was possibly 1951 or 1952. Ansco may have been using their own colour material to make the prints or printing onto Kodacolor paper.
In September 1953, The British Journal of Photography reported that Ansco Plenacolor was generally not available in the United States, although it has been given a limited area distribution for evaluation.
Plenacolor was never listed in the section Colour Materials for Still Photography, printed annually in the British Journal Photographic Almanacs of the 1950s.
The Amateur Photography diary for 1959 gives information relevant to Ansco colour transparency film. Further appears in a Focal PhotoGuide booklet, "All about Colour with Anscochrome", written by Keith Hornsby and published in 1959 (see cover image, left).
Subtractive colour material
with colour couplers embodied in the emulsion. Processed by the
manufacturers or their agents or by kits which they supply, but
discouraged as being uneconomic unless a user wished to process
several films over 'a short interval'.
In 1959, Super Anscochrome was the fastest reversal colour film available but could be speed increased to 200ASA by using a modified processing technique involving increased time in the first developer (step 1;16mins becoming 23mins) and the colour developer (step 6; 14mins becoming 16mins). All at 68°F = 20°C.
By 1971, Ansco transparency
film was being imported into the UK by GAF (Great Britain) Ltd;
Photo Products Division, PO Box 119, 99 Camberwell Station, London
Michael Talbert recalls using
Anscochrome 500 film in the mid 1970s, to photograph tube trains
in the deep level lines (possibly 1938 tube stock at stations
on the Bakerloo line). The light was so dim that even at 500 ASA
he could only just use a short enough exposure to 'freeze' the
movement of passengers. The 35mm transparencies were extremely
grainy, with a gritty appearance. Contrast was high.
Michael Talbert started making colour prints in 1969, using Kodak Ektacolor Commercial paper. He was a photographic colour printer in the 1970s, printing colour negatives mainly onto Agfacolor paper. He also had experience using about 10 types of Kodak paper, plus other makes, Gevacolor, Fuji, Paterson, Konica.
Michael now sets up and takes Retro fashion pictures, but prints them digitally.