The advantages which the new supersensitive film has over the present type of film are described, and comparative photographic characteristics of the two types of film are presented. In addition, the paper includes a brief discussion of the particular features involved in the use of the faster film, such as the difference in color sensitivity of the two types, and relative contrast, and the rendering of details in shadows and soft highlights. Users of the new film are cautioned against the danger of processing it when using the present safe lights, on account of the greater speed of the emulsion. The paper concludes with a description of the gray base which has been provided, mainly for the purpose of avoiding halation.