التصوير الملون بطريق الإضافة ٢_a .. كتاب التصوير الملون ، الكاتب عبد الفتاح رياض

Spirited blue rays layer

green sensitive layer

infrared sensitive layer

And separating them from the upper general support, each of them separately, and removing the two sensitive layers that dissolve in water, prohibition of clean

Film support

(fig. 33)

A strip of film bearing three sensitive layers separable from the film support

Multilayer Stripping Film

As a simplified means of obtaining Color Separation Negatives using any usual machine prepared as a basis for “black and white” photography, whether still or cinematographic, films were prepared (as shown in the figure) bearing three sensitive layers of gelatin. The upper (No. 1) is sensitive to blue rays, Then it is followed by a yellow filter (No. 2) that absorbs blue rays so that they do not reach the two lower layers. Layer 3 is sensitive to green rays, and layer 4 is sensitive to red rays

After exposure, and prior to showing, the film is dipped in water, which makes it easy to remove the upper layer from the film and transfer it to another support prepared specifically for that.

d

Then the green sensitive No. 3 layer is removed and transferred to a separate support, thus leaving only the red sensitive layer on the original film support.

Then each of the three layers is shown separately and in a solution of an appearance that has the same characteristics. We get three negatives separated by colors, each on a separate support. It is noted that by following this method, three color-separated negatives can be obtained, even if the subject that we filmed was moving. This is in contrast to the previously explained method on p

consecutive times

We took the form from the following reference: EVANS-Principles or Color Photography. P. 311, 2nd edition.
Three filters in front of the lenses (their colors are blue, green, and red)

The body being photographed

direction of pen movement

(Fig. 34)

Color cinematography according to the addition theory with a camera that has three lenses:

This method is known as the Gaumont Process (1) in relation to its inventor. It is also known as Simultanious exposure three color additive photography, in which a camera with three lenses is used, in front of one of which is a red filter, in front of the second a green filter, and a blue third in front of the third. Thus, each shot is recorded on the cinematic learning, three consecutive pictures at the same time. These are the images that become - after displaying the three negatives separated by colors. It is obligatory for the film to run in the camera at a speed (72 images per second), as it must not take more time to shoot each group (which consists of three pictures) than it takes to shoot one picture if the shooting was on a regular cinematic film that was prepared to be a black and white film in The usual movie camera.

After filming, the previous film is printed to obtain from it the last positive, representing a group

Color separated positive images. In order to display these images, a projection device is used that also carries three lenses, in front of each of which there is a filter, so that the image that was recorded in the imaging stage through the red filter is located - in the projection stage - behind the same filter. And so also for the photographer that registered during each of the other green and blue candidates. A serious defect appeared in this method. This defect is the difference of view (2)

Parallax caused by a distance between the three lenses. And this defect appears body

The closer the subject being photographed is towards the camera lens. extent can be estimated

The difference of view mathematically according to the following equation (3):

Divergence value = focal length x distance between the two lenses. Adrian cornwell, Color Cinematography, P. 277, 3 rd. (1)

edition. For the author of 146,145 of the first edition. Publisher The Anglo-Egyptian Library 165 Mohamed Farida Street (2) For first information about parallax, please refer to the camera book (3). We have taken this equation from Evans, Principles of Color Photography.
a movement

Maman blue filter

The body being photographed

The direction of movement of the fam

Ahmed candidate

candidate

green

(fig. 35)

Colored cinematography according to the theory of addition and with the use of a single-lens camera, in front of which there is a rotating disc holding the three filters:

This method is also known as the "Gaumont process", relative to its discoverer, and is also known as Successive exposures, three color additive.

photography: its discoverer used - a modification of the previously explained machine in (Fig. 34) - a single-lens cinema camera and in front of it a rotating disk divided into three sections, and in each section one is blue, the second is green, and the third is red, and when the film runs inside the camera, the disk that carries the filters rotates so that Each image (frame) is exposed through one of these three filters. Thus, he records on the film an image that was exposed through the blue filter, then a second through the green filter, then a third through the red filter, and so on. It is clear that filming in this way also requires that the film be run in the camera at a speed of 72 images per second, as each group (consisting of three pictures) should not take more time than it takes to show one picture if the movie was cinematic running in a filter machine.

Usual photography. Although this method overcame the defect of the space parallax that arose in the first method because of the distance between the lenses, yet another new defect appeared in the current method, as the position of the image of the moving object is not the same in the three consecutive images, because it is located Between recording each image and the next, there is a period of time in which the moving object has taken a step forward, and this appears in the figure above from the location of the dotted arrows over which the numbers 1, 2, 3, and 4 are denoted). This new defect is known as Time Parallax.

In the projection stage, a display device similar in theory to a camera is used, and in front of its lens are the three rotating filters, so that the image recorded by the red filter comes behind the red filter in the projection stage, because the three images follow one after the other on the screen at a speed sufficient to mix their colors together. It is clear that this method relies on the property of "persistence of vision", which can be briefly interpreted as the perseverance of the individual's perception of the visual image for a very short period of time after its demise. And so we realize

The mixed color image is from the successive speed of displaying the three color images on the screen. 1 - Adrian Cornwell, Color Cinematography, p. 277, 3rd edition.
- 122 -

Third: Obtaining the negatives of color separation by means of cinematographic cameras with one lens, and in front of it is a rotating disc divided into three parts, each of which carries a primary color filter, and the three images are exposed one after the other (Successive Exposure) and in the form of 35 explanations for that. Fourth: Obtaining color separation negatives by means of special beam splitting cameras, carrying one lens, and exposing the three images simultaneously (Figures 36, 37, p. 123, 38, p. 129).



Film, Necromatic

with blue

Manan sher transparent

green filter

Movie, Necromatic

(Fig. 36)

A fixed camera (for one exposure) that works on ray fission: (1)

(One Shot) or (Single exposure) beam splitting Camera.

When light rays pass through the lens into the camera, they are met by a semi-reflective mirror (a) (i.e. semitransparent mirror) that reflects about a third of the rays to the upper side, where they are met by a blue filter behind which there is a panchromatic film. Two-thirds of the rays (approximately) pass through this mirror. The first (semi-transparent) followed by (B), also semi-transparent. Here, some of them are reflected to the lower part and are matched by a red filter, under which is another panchromatic film. As for the last third of the rays falling on the mirror (b), it passes through it to the back and meets the third green filter, which is located directly behind it, the third film prepared for recording, the third image.

Ralph Evans, Principles of Color Photography, 1st edit. P. 285

Ahmed candidate

the movie

green filter

Blue filter

(fig. 37)

X-ray chromatography machine:

This instrument is known as Chromoscope, Photochromscope or Kromoskop. It operates according to the steps shown below:

1- The light rays pass through the lens to a semi-transparent mirror (B), through which a side of the rays is reflected and reflected on the prism (f) and then the prism (g) and then it is reflected on it as well. They pass through a blue filter (the lower one) to the sensitive parachromatic scale located at the back of the lens.

camera

2 - As for the other part of ! The rays falling on the semi-transparent mirror (b), then it is reflected from it until it reaches another semi-transparent mirror (c), and here the rays split again, and part of them passes into the prism (d), where it is reflected on its surface, passing through a red filter, so only the red rays pass until they meet The upper side of the photosensitive film

3- Another part of the rays falling on the mirror (C) is reflected from it to the prism (E), then it is reflected again on the prism (F) and passes through a green filter (in the middle) until it reaches the film at the back of the image.

Thus, we see that one film may contain three color-separated images, one of which was recorded through a red filter, the second with a green filter, and the third with a blue filter.

Fifth: Two types of films reproduced in color images according to a method

In addition, they succeeded as a business in some years, and in a limited way, and they are:

(1) Films, some of which carry elements colored in primary colors known as

The Mosaic Screen was in some movies

It is located inside the layers of the film (Fig. 40 p. 131) and was separated in
other movies