NAEB Engineering Newsletter (Dec 1955)

-9- In general, motion picture cameras designed for single sprocket operation, such as simultaneous sound and picture taking devices, use n B Wind*’ stock* Kinescope record¬ ers and Auricon cameras fall into this category* On the other hand, most contact film printers, for example the Bell and Howell Model J, load with "A Wind" raw stock* Where sound exposure and sound printing is not a factor, cameras and printers can usually be loaded with double perforated stock which, obviously, cannot be classi¬ fied according to "wind" in light of its accepted definition* Emulsion Position—Standard and Non-Standard A person who has operated 16mm. projectors is likely aware of the fact that some films thread-up with the emulsion toward the screen while other films project with the emulsion surface toward the lamp* The first of these positions (emulsion toward the screen) is defined by the Society of Motion Picture and Television Engineers as n STANDARD EMULSION POSITION"; the latter (emulsion toward the lamp) is defined as "NON-STANDARD EMULSION POSITION." In order to compensate for this slight change in the focal plane of the emulsion image, it is usually necessary to change the focus of the projector lens a small amount to obtain maximum sharpness. Similar compensa¬ tion for sound focus is desirable but must be effected by an adjustment of the tone control, unless the projector is equipped with controls for the adjustment of the sound optical system. Inproper focus in the sound optical system results in the loss of high frequencies and impaired signal-to-noise ratio of the sound reproduction* The differences in emulsion position result from the fact that in the contact print¬ ing of one film onto another the resulting impression is a mirror image of the origi¬ nal rather than an identical image. This paradox can be illustrated very simply by having a person stand before a mirror and observing the reflected image. In such a situation, when the subject moves his right hand, the image moves its left, etc. When contact printing from a negative film onto a print copy, it is necessary to have the two emulsion surfaces facing each other in order to assure the maximum in transmitted detail. Therefore the print copy becomes the mirror image of the nega¬ tive/ in which case; left becomes right and vice versa, when the two films are com-. pared symetrically and with their emulsions facing the observer. Should the origi¬ nal and the copy be run consecutively through a projector, it would be necessary to thread up the latter in such a way that its emulsion would face in the opposite di¬ rection from the former if one wishes to preserve the same "left-to-right" relation¬ ship of the projected image. Such a switch is possible in the case of "silent" type 16mm. film where the double sprocket holes permit running the film in either manner* However, in the case of 16mm. sound film, which utilizes only one set of sprocket holes, there is only one way in which to pass the film through the projector unless one runs the film "tails first" and thus produces an image and sound running in reverse order.’ Accordingly, the proper "left-to-right" relationship must be established during processing and printing operations in such a manner that normal projection is possible. These op¬ erations may produce a print having either "Standard" or "Non-Standard" emulsion po¬ sition, depending largely on the number of printing operations required to integrate various scenes and sound tracks into the desired release copy. It seems obvious therefore that persons engaged in film processing and printing must ascribe certain types of nomenclature to the inherent image relationships which exist on the film being handled. Since the processing procedures in a single production may involve several sound and picture printing operations on diverse film stock, strict adherence to such uniform nomenclature and procedure is mandatory in order ... to eliminate prints in which words appear backward etc.