Vivex was a modification of the three-colour carbro print process,¹ the main difference being the use of Cellophane as the temporary support rather than celluloid. This enabled the individual gelatine images to be manipulated when being superimposed to give better registration. Slight differences in the images could result from movement between the three exposures in a repeating back, the Cellophane-backed tissue could be stretched and squeezed with the fingers to get better alignment.

Colour Photographs (British & Foreign) Ltd. (CPL) operated the Vivex process between 1930 and 1939 producing prints from three-colour separation negatives, the service was aimed at professional photographers. A grey scale and colour chart was to be included in the negatives.

Ordinary three-colour carbro prints produced very good results but the process was time consuming and did not lend itself to commercial studio work where its use would have made the cost of a print excessive. By standardising the different stages in producing a print and operating in a controlled environment CPL were able to produce high-quality prints at a reasonable cost.

The Process

This piece is largely taken from Coppin & Spencer's paper of 1948 published in the Photographic Journal.

• All three prints from the separation negatives were made on a single sheet of bromide paper and treated as a single unit to ensure common development, fixing and washing. The three pigment tissues were also sensitized together and developed together.
• A single sensitizing bath was used (rather than the normal two) of potassium ferricyanide, potassium bromide, chromic acid and tap water.
• The sensitised tissues were laid face upwards on a duralumin sheet and brought into contact with the bromides by using a mechanical squeegee (something like an old-fashioned mangle). After 10 - 15 minutes the bromide print was stripped off.
• The tissues were sprinkled with a mixture of water and methylated spirit. A Cellophane sheet, previously washed and soaked in the mixture of water and methylated spirit, was lightly squeegeed to the surface of the tissues. The tissues were then dried.
• The Cellophane/tissue/duralumin was lowered, with the Cellophane down, onto a large sheet of celluloid immersed in warm water which formed part of the developing tank.
• The duralumin was removed along with the paper backing of the tissue. The tissue was attached to a drum and rotated in warm water for three minutes to remove the soluble gelatine. On removal from the developing bath the tissue was coated with a gelatine solution and then dried.
• At assembly, the yellow image was transferred to paper and partly dried, a formaldehyde bath allowed the Cellophane support to be removed. The magenta and cyan images were then superimposed.

The tissues were supplied by the Autotype company to a slightly different specification to normal.

Automatic three-colour back

CPL produced a three-colour back, its use was not essential for the production of Vivex prints but, being driven by clockwork, it was quicker than an ordinary three-colour back. The back was developed by L.W. Oliver of CPL.

Rather than using the normal red, green and blue filters with panchromatic plates it was recommended that an Ilford Soft-gradation (panchromatic) plate was used behind the red filter, and Agfa isochromatic plates behind yellow and magenta filters for the green and blue images respectively. This arrangement required less exposure time.

The back shown in Spencer, 'Colour Photography in Practice' and Coote, 'History of Colour Photography' is different, and probably later, to the example shown above, Coe, 'Colour Photography' illustrates a similar model.

The exposure is made by a shutter in the camera operated by a cable release that connects to the repeating back, the shutter itself is set to B.

The back is driven by a large clock spring in a shallow container, below this is a drum with a spiral groove, below the drum is a cam plate that operates the shutter release and below the cam are two pins that control the movement of the slide carrier. The slide carrier consists of a ground glass focusing screen, three colour filters and a fitting for a removable dark slide. Wrapped around the drum is a wire loop, the loop passes into a cylinder running most of the length of the back, within the cylinder the wire is attached to both ends of a piston (described in the patent as a plunger within a dashpot).

When released for an exposure the spring will cause the drum to rotate which will pull the piston along the cylinder, the speed of rotation of the drum is determined by the movement of the piston. The cylinder is filled with liquid (cedarwood oil), as the piston is pulled along the cylinder it displaces the oil into a by-pass tube, the oil is then able to return to the cylinder behind the piston. Within sections of the by-pass tube are three valves which impede the flow of oil. The settings on the valves correspond to the individual exposure of the three images. In this way the movement of the piston and hence the drum is varied.

The slide carrier is moved by pins engaging in two slots on the slide carrier each side of the focusing screen. The movement is best described by looking at the rotation of the drum/cam/pins. After focusing, the slide carrier is moved to the left until it abuts one of the pins this brings the first plate into position behind the lens. The mechanism can now be released.

• During the first half revolution -
  Shutter released by the cam and the first exposure is made.
  The valve on the far right is in operation.
• Second half revolution -
  Shutter closes.
  One of the pins engages the left most slot on the slide carrier and pulls it to the left.
  The piston is free to move as there is no valve in this section of the by-pass tube.
• Third half revolution -
  Shutter released for the second exposure.
  Middle valve in operation.
• Fourth half revolution -
  Shutter closes.
  One of the pins engages the second slot of the slide carrier and pulls the carrier to the left.
  The piston is free to move as there is no valve in this section of the by-pass tube.
• Fifth half revolution -
  Shutter released for third exposure.
  Left most valve in operation.

When in the focussing position a small plate rocks a lever which opens the shutter, when the carrier is moved to the left the shutter closes.

Cameras

The obvious limitation of a three-colour back is that it is not suitable for moving subjects. CPL investigated a Vivex one-shot camera as early as 1930, according to an article by Dr. D.A. Spencer the company was in discussions with Major Adrian Klein (later Cornwall-Clyne) who had produced a camera using pellicle reflectors rather than glass.² A pellicle being thin did not produce a secondary reflection from the rear surface which was out of register with the primary image produced by the front surface. The pellicles were manufactured by H.O. Klein (no relation to Major Klein).

CPL then manufactured a test camera using pellicles to the design of L.W. Oliver and H.G. Eckert, the camera was for quarter-plates and was fitted with an f4.5 10.5" lens. Following this one or two further cameras were made, one camera was made by Bellingham & Stanley Ltd. From diagrams it can be seen that the two reflecting surfaces are at right angles to each other giving images at the top, bottom and back of the camera. The camera used the unusual filter arrangement found in the automatic back. It is not clear what role Major Klein played in the detailed design of the camera, since he had previously patented a three-colour camera using pellicles and with the same mirror arrangement it must be assumed that he played some role.

A second model of camera was developed by Taylor, Taylor & Hobson and patented by T.W. Clifford and Kapella Ltd. This camera used glass reflectors. The mirror arrangement was different to the earlier camera, the mirror immediately behind the lens produced an image at the top of the camera, a second mirror produced an image at the side, the third image was at the back of the camera. It is this model that Madame Yevonde is using in the well-known photograph.

Colour Photographs Ltd

The company was formed in 1928 to exploit a patent for a tri-pack. This must have proved unsatisfactory as Dr. D.A. Spencer was brought in as a consultant. The business model of the company must then have changed to become a colour print service. Spencer, who joined CPL as Technical Director, devised the working methods used in the factory and introduced modifications to the carbro process such as the use of Cellophane as a temporary support and a single bath sensitiser.

The name of the company was changed from Colour Photographs to Colour Photographs (British & Foreign) in 1928. CPL operated between 1930 and 1939, it ceased trading as a result of the war. The factory was in Victoria Road Willesden. In the first few years of the company a large proportion of their work was for the process (graphic arts) trade.

L.W. Oliver was works manager at CPL from 1928 to 1932 and designed a lot of the specialised equipment, later, Frank Coppin was works manager.