We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
August, 1953
HOULT, HARPER AND STAFFELL : PROCESS PROJECTION IN COLOUR
yi
Ektacolor Negative Film is only supplied as Type B at present, so a Wratten No. 85B filter must be used when exposing to daylight or high-intensity arc. The use of other colour correction filters is not advised, as special colour effects such as night shots are best introduced during printing. The negatives should, therefore, be shot straight ; they will then serve for any type of effect that may be required.
Incorporation of a grey-scale in the picture is also unnecessary, as the colour balance is adjusted in printing to match the prevailing colour balance in previous scenes.
Printing the Ektacolor Negative
Ektacolor Print Film, designed for making colour transparencies from Ektacolor Negative is used for this purpose.
Exposure can be made by contact or projection. Projection is normally used as negatives are shot 5-ins. by 4-ins. and reduced to 3-ins. by 2.2-ins., the size of the projector gate.
The light source is incandescent at approxmately 3,200° K. This colour temperature is not critical and adjustment can be made with colour correction filters on the enlarging lens. U.V. is permanently filtered out with a Wratten No. 2B filter over the light source. Colour control is obtained by using colour correction filters in combinations as required. These filters comprise a set of primaries — namely, red, green and blue, and their complementaries, cyan, magenta and yellow — 3 of each in steps of 0.05, 0.10 and 0.20—18 filters in all.
Colour control is of such latitude that day shots can quite easily be converted into night shots.
When exposing print film it is advisable to adjust the exposure time by the lens stop in order to avoid the effects of differing reciprocity law failure in the three layers.
After processing and drying, the print film is fixed emulsion side down on to a 3^-ins. by 3^-ins. square of glass with 10 per cent gelatine solution. The acetate base is then stripped off leaving only the colour layers on the glass.
The colour balance must be agreed and fixed before slides are prepared for projection. Responsibility for approving colour balance is with the art director who usually matches the balance of previous scenes.
Once slides are made it is not easy to alter them. A certain amount of matching between screen and foreground can be effected by local colouring of the foreground with paint or light, or by directing additional lights at the screen. These are only makeshift methods and do not adequately replace a decision made in good time by the art director.
Similar considerations (apart from the need for monochrome lining-up plates) apply to the printing of 35mm. negative-positive colour films used as moving plates. This work is carried out by the motion picture laboratory.
(Mr. Harper concluded by showing a number of slides made as plates for the film Penny Princess.)