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.
Screen-Plate Practice 511
A. von Palocsay4 recommended pinachrom, using :
Pinachrom, 1 : 1,000 ale 8 ccs.
Absolute alcohol 200 ccs.
Water 800 ccs.
Time of bathing 2 minutes, and drying as rapidly as possible.
C. Adrien5 found that although this method of bathing gave greater general speed, yet it did not increase the green sensitiveness sufficiently to give good rendering of the foliage of trees, etc., as pinachrom is not a sensitizer for green. Von Hiibl6 stated that by the use of the following bath, the sensitivity of the Autochrome plate might be increased five times. Three stock solutions were prepared :
A. Pinacyanol, 1 : 1,000 ale 5 ccs.
Ammonia 3 drops
Alcohol, 90 per cent 50 ccs.
Water 100 ccs.
B. Exactly the same as above but with
Pinachrom, 1 : 1,000 ale 2 ccs.
C. As above but with
Pinaverdol, 1 : 1,000 ale 2 ccs.
Instead of the pinachrom. The actual sensitizing bath was:
A solution 67 ccs.
B solution 466 ccs.
C solution 466 ccs.
Bathe for 5 minutes and dry in the dark without washing.7
F. Monpillard8 pointed out that old hyper-sensitizing baths can not be made to give such good results by increasing the time of immersion. In old baths the greater part of the pinacyanol becomes inactive, and the plates are sensitized for yellow and green, but not for red. Therefore, a fresh solution should always be used, and as several plates can be bathed one after the other it should be then thrown away, for the bath may be made up some little time in advance. The time of immersion may vary within wide limits, but should never be less than 3 minutes. The degree of dilution may also be varied, but it is preferable to keep to that which experience has shown to be the best. A great dilution necessitates longer immersion, and it is as well to avoid this, as there may be pinholes in the gelatin emulsion through which the liquid may find its way into the screen coating, and cause stains. Experience has shown that provided the dilution and the time of immersion remain the same, the results obtained by hyper-sensitizing do not appreciably vary with differences of temperature.
M. Jove9 stated that he had found a commercial preparation for hypersensitizing, which was very satisfactory before the war, would no longer work well, and this he ascribed to the better panchromatization of the Autochrome emulsion. He had, therefore, fallen back on Simmen's method, and by adjusting the formula as directed, the quality of the added sensitiveness could be varied according to the requirements. The basis