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.
MASKING 283
and the combination is printed by contact upon Wash-Off Relief material* The automatic character of the masking now becomes evident. The masked negative should be printed with green light. Therefore the intensity of the light at any one point is first reduced to the extent to which the cyan image deposits green densities at that point, and then is modulated by the greenfilter negative lying below the mask. This would require that the Wash-Off Relief emulsion be green-sensitive, which it is not. But the amount of green masking is approximately the same as the blue, so that but very little difference would be obtained if the printing of the magenta matrix were done with blue light instead of green. This is taken care of by the emulsion itself, since it is truly blind. The magenta matrix is processed to completion, and is dyed to the exact extent that would be used in the final image. The two matrices, dyed cyan and magenta, are combined and the combination placed in registry with the blue-filter negative. Now a contact print made from this combination will be correctly masked for the poor blue transmissions of both the cyan and magenta dyes actually used, because the exposing light must first pass through the cyan and magenta positive images before passing through the blue-filter negative. Therefore the light is modulated, first of all to the extent of the blue densities deposited by the dyes, then by the bluedensity negative.
As disclosed by the Eastman technicians, this semi-automatic scheme is useful only in the case where same-size images are made. The scheme is termed semi-automatic because the green densities are corrected by the blue absorptions of the cyan dye, rather than by the green absorptions. But as noted above, the two approximate each other very closely. It is possible to generalize the technique to make it useful for enlargement. The masks, in this case, are made by contact and registered with the negatives in the manner disclosed above. But these are not used for the final print. New matrices are made by projection through the masked negative, so that enlargements to any desired degree can be obtained.
Should one use other methods of making the positive prints, a similar type of technique could be evolved. Let us suppose that the print is to be made by color development. The red-filter negative is first printed by contact upon a film, and this is converted into a cyan image by coupler development (cf . chapters on Color Development for details). The colored image is registered with the green-filter negative, and the magenta image printed by contact from this combination, etc. With different systems, it may be advantageous to mask the red-filter negative, as well as the others. This is a rather obvious extension of the present technique.
The current popularity of the monopack films typified by Kodachrome, bids well to extend the idea of masking to still another field, the making of separations from monopack transparencies. Here more than anywhere else, a masking technique is desirable. This matter is discussed rather critically by J. S. Friedman in several of his columns in American Photography (cf. I.e.,