Journal of the Society of Motion Picture Engineers (1930-1949)

simply to change the slitting dimensions, i.e., the dimension A in the Standard, from 0.629 in. ± .001 to 0.628 in. d= .001. Objections were raised to this method of changing the standard be cause it was felt that many people would consider that this meant a true reduction in width of film as it is used and would, therefore, reduce the width of the projector gates, camera gates, printer gates, etc., with the results described above. In order to avoid this difficulty, it was proposed that the Standard for dimension A be written 0.6285 in. =b .0015. This way of writing the dimension would lay claim to the greatest width of the previous standard, namely, 0.630 in., and yet would permit film manufacturers to reduce their slitting width as much as required so that their low-shrink film would not exceed the width of the highshrink film as previously manufactured. This idea was rejected because some members of the Committee felt that it would make it appear as if the change might be intended to permit less accuracy in slitting width than heretofore. For the above reasons the Film Dimensions Committee finally agreed to recommend two standards. The old standard was to be kept the same as previously except that an asterisk was to be inserted above dimension A referring to the statement "For low-shrink film dimension A should be 0.628 in. ± .001 and dimension E, 0.0355 in." A definition for low-shrink film was included in the standard. The above method appeared to our Committee to take care of the difficulty in a fairly practical way, and this is the standard that is being recommended to ASA. On the 9th and 10th of June at a meeting of Technical Committee No. 36 (Cinematography) of the International Standards Organization (ISO) this matter was further discussed. The three propositions as outlined above were placed before the Committee. The members of the Committee were unanimous in agreeing that some actual change in slitting should be adopted. The British delegates were insistent that their standards body would never accept different standards for high-shrink and lowshrink film and that they could not accept the increase in tolerance. The only one of the three proposals which they would accept was the reduction in the standard as outlined in the first of the above propositions with an additional statement somewhat as follows: "Experience shows that it is common for film to expand when exposed to high relative humidity. Allowance should be made for this factor in equipment design and in no case should the equipment design fail to accommodate a film width of 0.630 in., 16.00 mm." Rather than see the matter deadlocked, the American group as well as the French and German groups agreed to this modification. Most of us felt that all three proposals were * identical in actual content and that any one of them would be satisfactory as an International Standard although we still preferred our own choice for the American Standards. The actual standards covered by the work of the Committee are: PH22.5, 16mm Double Perforation; PH22.12, 16mm Single Perforation; and PH22.93, 35mm Low-shrink Film. These have been submitted by this Committee to the Standards Committee of the Society. It might be mentioned that the standards for 35mm low-shrink film intended to be used as camera raw stock do not call for a narrowing of the width, nor for other changes that seem quite logical from the point of view of shrinkage alone. The reason for this is that no changes have been made, however logical they may seem, without consulting the people in the trade who are using the film every day. This policy of considering the needs of the user is very desirable in simplifying the procedures and in preventing what might possibly be unnecessary or undesirable changes E. K. Carver: Film Dimensions Report 425