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.
very costly and delicate, and up to the present day their use has been very limited.
I will not omit to mention the simplest of the methods that is applicable to the three-chromatic selection for photography,, the so-called < Tripack » which may be adapted to any camera* In the Tripack, three films are superposed, and are separated by coloured strata; the sensitized stratum itself, suitably coloured r can act as filter for the successive film. This process represents the maximum of simplicity, but the colour selection is always imperfect, owing to the lack of a sensitive stratum capable of selecting the rays: should this be possible, also coloured filters^ such as we are compelled to use in the Tripack, the action of which is now far from being perfect, might be found adequate.
An English Company is stated to have recently succeeded in obtaining fairly good results by this means, but we are sceptical on this point.
On the whole, it does not look, at least for the time beings as though the Tripack method can be applied to colour cinematography.
Importance of Chromatic Sensitiveness in three-colour processes.
As we have already stated, the three-colour process has become a practical realization, owing mainly to the discovery of chromatic sensitizers. Any process in colour photography or cinematography, such as the autochromatic process, interferential chromophotography (a process which is important mainly for scientific purposes), the new process of the lenticular film, etc., need a sensitive stratum with a sensitiveness extending to all the rays of the spectrum. This stratum, which is called panchromatic, has now been found, and its practical realization has required long and difficult research work in chemistry relating to dyeing materials. Although it may be said that the research work relating to chromatic sensitizers was somewhat helped by the principle discovered by Vogel in 1870, which formed the starting-point of this important technique, namely, that Silver Bromide can
179 —