Motion Picture Operation, Stage Electrics and Illusions A Practical Hand-book and Guide for Theater Electricians, Motion Picture Operators and Managers of Theaters and Productions

The wireman should not fail to consult local rules or inspection departments as to whether any rules conflict with those given below. He must be warned to consult local authorit...

=Aberration.=--The convergence to different foci, by a lens or mirror, of rays of light emanating from one and the same point or the deviation of such from a single focus.

The general rule is that all wires in theaters must be in conduit or armored cable. Metal molding is not considered suitable for the stage side of the theater. There are, howeve...

_Setting and Adjustment of Carbons._--To project a picture upon a screen properly is an art and requires close study and some knowledge of all the factors involved. The most imp...

A diagrammatic sketch of the essentials of a good motion picture machine is given in Figure 28. This does not represent any machine in particular and no machine exactly like it...

_Tools._--First of all provide a suitable and sufficient set of tools. There should be an assortment of screw drivers, large and small, to fit the different sizes of screws used...

_Voltages Required._--The commercial distribution of electrical energy is at voltages of 110 or 220, in most cases, and occasionally runs as high as 550. The direct-current arc...

_Construction and Ventilation._--The operating room should be built of fireproof material, such as cement, brick, or tile. If it is of wood, it may be made nearly fireproof by l...

_General Discussion of the Electrical Arc._--The name of the electrical arc lamp is derived from the arch-like appearance of the vapors which give out the light when the carbons...

_General Requirements._--In most cities it is required that theaters be built in locations which give free space for exits on two or more sides. A common requirement is that two...

_Two and Three-Wire Systems._--If the theater electrician will take the trouble to trace the circuits in the building to their supply, he will find them entering the building ei...

Light may be reflected from opaque or transparent bodies such as glass. In the case of transparent bodies, the reflected rays are not noticeable unless the ground behind the ref...

Light is emitted from a luminous body. A luminous body is one in which all of the particles are conceived to be in violent motion, which motion is transmitted to a supposed ethe...

_Film Making and Characteristics._--All film is of celluloid. The commercial film used for the projection of motion pictures comes in long strips, is about one and three-eighths...

Strictly speaking there are no pictures of motion. What we see as such is simply an optical illusion. This illusion is produced by presenting a series of pictures of an object i...

If a straight stick or pencil be plunged into a vessel containing water, it will appear to be bent. The reason for this appearance is given in detail in Figure 79. The only ligh...

The eye is easily deceived and is also very inaccurate in its judgment. In Figures 109 to 111, all of the lines are of precisely the same length, yet they appear to differ consi...

In most optical instruments, lenses are used for the purpose of gathering a large number of rays of light and altering the apparent direction of the rays so that an enlarged pic...

_Operation of Generators._--The generator should be located in a clean dry place. If it is belt driven, the belt should be run horizontal if possible and so that the slack side...

The joint resistance of any number of resistances connected in parallel is the reciprocal of the sum of the reciprocals. The reciprocal of a number is 1 divided by that number:

Through the medium of our eyes we see objects by means of the light which is reflected from them. This light enters the eye and forms an inverted image of the object upon the re...