آلات التصوير الملون التي تعمل على انشطار الأشعة .. كتاب التصوير الملون

Beam Splitting Color Cameras Beam Splitters With this type of machine, three color separation negatives can be obtained from one shot. These machines are characterized by the presence of x-rays and their division into three sections after they enter the machine. The rays are split by flats or semi-reflective bodies (i.e. they reflect part of the rays and the rest is permeated by them. These flats are located between the lens and its focal plane. These bodies or flats may be

of any of the following types:

(1) Semi-reflecting mirrors: It is faulty for them: the rays through them are refracted to the extent that they cause distortion 1- By passing

Image Distortion.

- It causes a second reflection on the back surface of the glass.

(b) Very thin surfaces of collodion or cellulose covered with a shiny metallic layer:

Which is allowed. her by reflection. These surfaces are usually found in still cameras. (C) Prisms with a silvery, reflective surface: they are damaged by what absorbs the rays when they penetrate the prism glass. Some types of these machines may suffer from a serious defect, which is inequality

In view of the aforementioned defects, it was found that it is much better to replace the glass with very thin surfaces of collodion or cellulose that are less than an inch thick, and placed inside the machine, stretched between a completely flat metal frame. It results from the refraction of rays and then their reflection on the other surface. These flats are coated with very thin layers of metal (by deposition of aluminum vapor on these flats in vacuum places) in a manner that guarantees maintaining the required ratio between the amount of rays that are allowed to permeate, and those

The intensity of image illumination, and this is explained in Figure (39) p.

(1) A type that carries two semi-transparent and semi-reflective surfaces, in which the negatives of color separation are recorded on three films located in three focal planes of the lens (Fig. 36, p. - blue ) . These films may be of the panchromatic type, or one of them may be panchromatic, the second orthochromatic, and the third sensitive to blue rays.

(2) Another type that bears one flat, semi-transparent and half-reflective, and is not machine-made. Only two focal planes.

In this last type, we use films of another type known as Bipack.plus one, in which two films meet together, with their surfaces facing each other, while the third film is separate (Fig. 38, p. 129). The first film is sensitive to blue rays and is intended for blue recording, while the other two films are panchromatic, one of which is intended for green recording and the other only for red recording.

It is usual for the machine manufacturer to recommend the use of films with a certain sensitivity and spectral sensitivity that are usually suitable for optical filters and the spectral characteristics of semi-transparent and semi-reflective surfaces.

After color photography is associated with this last type of machines and films, it is called the Technicolor method, and it is one of the color photography methods that have proven their excellence and superiority in the modern era. These films are specially manufactured for Technicolor, by Eastman Kodak, and are characterized by a special degree of shrinkage: Low Shrinkage. The Technicolor film producers (in Hollywood and London) monopolized the manufacture of these machines. The number of all large-scale global production does not exceed forty machines, d. The machines that are used in this.

And after the end of the exposure, these films begin to be shown so that the contrast degrees in the three films are completely equal, and thus color-separated negatives are formed, from which the color-separated positive images are printed, then other processes are performed to dye the three images (we will return to their explanation when we talk about the processes of printing color images)