Selecting Your Film Film Datasheets Film Types, Names and Numbers Film Decsriptions Film Base Edge Numbers EASTMAN KEYKODE Numbers Year of Film Manufacture - Date Code Symbols Selecting Your Film Before selecting a specific film, you will have to answer a number of basic technical and aesthetic questions about the entire production. The answers you provide will help greatly in the selection of the films that will best translate your concepts into moving pictures on a screen that convey your intended message accurately, completely, and effectively. You should consider the following factors because they directly affect your choice. Format Will the finished prints be 70 mm, 35 mm, or 16 mm? Who will be the audience? What quality do we want? Will it be shown only in a theater or on television too? Number of Finished Prints If you need only one finished print and you need it fast, a reversal film designed for direct projection is ideal. If you are producing several prints, select the camera film with an eye toward the economics of the various film printing systems. The Finished Form of the Picture Should the finished film be in color or in black­and­white? What feeling should the film convey? The sharp distinctions in hue and density provided by a color film image can convey more information than the same image composed of shades of gray. Filmmakers should not assume, however, that color is always more interesting, or that black­and­white is always less expensive. Should the filmbe silent or should it have sound? Answers to these questions depend on the purpose of the film and the audience it is geared toward. Lighting Will the subject be filmed indoors or out? Can you control the light? Some films are designed specifically for low levels of light. All films are balanced for particular kinds of lighting. Will your film give you an accurate record of the colors in the scene if you make the motion picture only in the light available to you? Filtration If you have to use several filters to compensate for uncontrolled elements in the scene or in the lighting, will the film be fast (sensitive) enough to record a high­quality image? Processing and Printing Facilities Few laboratories process every type of film. If your laboratory processes only color film, you will have to send your black­and­white film to another lab. You can avoid much anxiety by getting to know the personnel at the laboratories and explaining your special needs to them. It may be worthwhile to select films that you can have processed by a laboratory familiar with your needs. Film Datasheets Kodak film datasheets are the best source for technical information about EASTMAN Motion Picture Films. Each datasheet consists of four or more pages of detailed technical information for a particular film. These sheets provide much useful information for the careful and knowledgeable reader. In general, the discussion of professional motion picture films, a typical datasheet that provides information about motion picture film applications. Datasheets differ for negative and laboratory films. A camera film datasheet, for example, does not contain paragraphs titled `printing Conditions" because printing conditions are only relevant to laboratory and print films. Film types, Names, and Numbers Film production­from recording motion with a camera to projecting the image on a screen or television­often involves three different kinds of film. Camera Film is used to record the scene. Many kinds of camera films are available for the many conditions under which subjects must be filmed. Laboratory films are used to produce the intermediate stages needed in the lab for duplicating special effects, titling, etc. Making and working with intermediates also protects your valuable original footage from potential damage. Print film, on the other hand, is used for both the first workprint and for as many copies as are needed of the final edited version of the project. Many people in the motion picture industry refer to films by code number (5296, for example) rather than by name (EASTMAN EXR 500T Film). This four­digit number is displayed on the film datasheet with the name. The first of the four digits indicates the width of the film. When the first digit is 5, the film is 35 mm or wider; a 7, on the other hand, indicates an 8 or 16 mm film or a film that will be slit down to narrower gauges. The first digit of ESTAR Base film is a 2, for all widths. When a film is available in both the 16 mm and 35 mm widths, both appear on the datasheet. The name also indicates properties of the film. EKTACHROME indicates a reversal color film. If the film name includes a number, like EASTMAN EXR 500T Film, the number designates the exposure index­500 in this case. The letter­T in this example­indicates color balance. EASTMAN EXR 500T Film, therefore, is tungsten balanced. The important thing to remember about the name and number is to use both accurately when ordering film or film datasheets. Film Descriptions The first paragraph of a typical datasheet is a brief description of the overall characteristics of the film. Negative Camera Films Negative films produce the reverse of what our eye sees in the scene and must be printed on another film stock or transferred to videotape for final viewing. Since at least one intermediate stage is usually produced to protect the original footage, negative camera film is an efficient choice when you are planning significant editing and special effects. Printing techniques for negative­positive film systems are very sophisticated and highly flexible; hence, negative film is especially appropriate for complex visual impact. All negative films can go through several "generations" without pronounced image deterioration. Base Manufacture of Film Base The film base is the flexible support on which the light­sensitive emulsion is coated. Requirements for a suitable film base include optical transparency, freedom from optical imperfections, chemical stability, photographic inertness, and resistance to moisture and processing chemicals. Mechanical strength, resistance to tearing, flexibility, dimensional stability, and freedom from physical distortion are also important factors in processing, printing, and projection. Two general types of film base are currently used by Kodak­cellulose triacetate (acetate) and a synthetic polyester polymer known as ESTAR. (The words triacetate and acetate will be used interchangeably throughout this book.) Cellulose triacetate photographic film base is made by combining the cellulose triacetate with suitable solvents and a plasticizer. Most current EASTMAN Motion Picture Films are coated on a cellulose triacetate base. ESTAR Base, a polyethylene trephthalate polyester, is used for some EASTMAN Motion Picture Films (mostly intermediate and print films) because of its high strength, chemical stability, toughness, tear resistance, flexibility, and dimensional stability. The greater strength of ESTAR Base permits the manufacture of thinner films. ESTAR Base films cannot be spliced with readily available commercial film cements. Splicing of these films must be done with transparent tape or an ultrasonic or inductive heating current to melt and fuse the film ends. Antihalation Backing Light penetrating the emulsion of a film can be reflected from the base / emulsion interface or the base itself back into the emulsion. As a result, there is a secondary exposure causing an undesirable reduction in the sharpness of the image and some light scattering, called halation, around images of bright objects. A dark layer either on or in the film base will absorb and minimize this reflection, hence it is called an antihalation layer. Three methods of minimizing halation are commonly used: Rem Jet: A black­pigmented, non-gelatin layer on the back of the film base serves as an excellent antihalation and antistatic layer. This layer is removed during photographic processing. Antihalation undercoating A silver or dyed gelatin layer directly beneath the emulsion is used on some films. Any color in this layer is removed during processing. This type of layer is particularly effective in preventing halation for high­resolution emulsions. An antistatic layer is sometimes coated on the back of the film base when this type of antihalation layer is used. Dyed film base: Film bases can also transmit or "pipe" light that strikes the edge of the film. This light can travel inside the base and fog the emulsion . A neutral density dye is incorporated in some film bases and serves to both reduce halation and prevent light piping. This dye density may vary from a just­detectable level to approximately 0.2. The higher level is used primarily for halation protection in black­and­white negative films. Unlike fog, the gray dye does not reduce the density range of an image, because it, like a neutral density filter, adds the same density to all areas. Therefore, it has no effect on picture quality. Edge Numbers-Key Numbers Prior to 1990 Edge numbers (also called key numbers or footage numbers) are placed at regular intervals along the film edge for convenience in frame­for-frame matching of the camera film to the workprint. The numbers are latent image* printed along one edge outside the perforations on 35 mm and 65 mm film and between the perforations on 16 mm film. Most numbers are sequential, occurring every 16 frames on 35 mm and 65 mm film, and every 20 frames (or 6 inches) on 16 mm film. Until a new edge­numbering system was devised, 35 mm film had five sequential latent­image footage (key) numbers. A series of letters and numbers appeared to the left of the footage number that were a manufacturer's code. On 16 mm, there were either five or seven digits. The 16 mm footage number appeared every foot until the 1970s when it appeared every six inches (20 frames). All current Eastman camera films and some Eastman laboratory films are edge numbered at the time of manufacture by exposure to light. Some black­and­white laboratory films are numbered with ink. EASTMAN KEYKODE Numbers In 1990, Eastman Kodak Company introduced a new edge­numbering system that was included on all Eastman camera films. The new system incorporates EASTMAN KEYKODE Numbers which are also in machine­readable bar code. A variety of commercially available scanners can read the standardized bar code. In this improved format, the human­readable key number consists of 12 highly legible characters printed at the familiar one­foot interval (16 frames, 64 perforations) on 35 mm. The same human­machine­readable system is available for 16 mm, but at six­inch (20 frame) intervals. On 65 mm, the number repeats every 16 frames. Another method of edge numbering is very often used by motion picture laboratories Processed film is sometimes numbered on the base with ink. This numbering does not interfere with the manufacturer's edge numbers because the lab numbers are ordinarily printed on the opposite edge of the film. Normally, both the original camera film and the workprint are identically edge­numbered for later ease in matching. Each laboratory will use these additional numbers for their own or the customer's particular needs. KEYKODE Guide 16mm KEYKODE Guide 35mm KEYKODE Guide 65mm The above files require Adobe Acrobat® Reader Version 3 *Latent image: The film edge is exposed by a printer mounted at the perforator to produce an image visible only on processed film. Processed Film The film strip reference number affixed to the can of raw stock film also appears as a latent image on the film itself. On all camera films prior to 1990 and the usage of EASTMAN KEYKODE Numbers, the combination of manufacturer s code (an uppercase letter for 35 mm or a trailer end marking for some 16 mm), and latent­image edgeprint was placed on the film to help identify processed film. A summary of this information follows. Year of Film Manufacture Date Code Symbols There may be many important reasons for knowing the year an older motion picture film was manufactured. For instance, you may need to know the type of film base, especially if you are sorting between nitrate and safety base film. There is no readable numeric date on Eastman motion picture film products prior to 1990; however, most of our motion picture film products have a date code symbol. A date symbol, designating the year of manufacture, is incorporated into the edgeprint legend of almost all 8 mm, 16 mm, 35 mm, 65 mm, and 70 mm films. Three different sets of symbols, having either one, two, or three characters, were used prior to 1990, the year that KEYKODE Numbers started appearing on all color and some black­and­white motion picture film products, except print films. The only four years with a single character in the symbol were 1916, a circle; 1917, a square; 1918, a triangle; and 1929, a plus sign. For the years 1928 and 1948 there were three circles. All other years until 1982 exhibited two characters which repeated every twenty years. For example, the same symbol appears for 1921,1941,1961, and 1981. Starting with 1982, a third character was added that allows for many more years before repetition. Beginning with KEYKODE Numbers (1990), the film date code is represented by two alpha designators. Below are the date code, or yearly, symbols beginning with 1960 and ending with 1991. These may be either open or solid. With the codes prior to 1982 repeating every twenty years, these represent all years beginning with 1919. If the symbol on your Eastman motion picture film does not match those previously described or listed below, please contact your regional Kodak office. Please be aware that color print film does not have KEYKODE Numbers. The symbols as listed below will continue as a part of print film year­of­manufacture identification. Film Product Edgeprint Identification To further help identify Eastman motion picture film products without KEYKODE Numbers, each 35 mm product has a letter as the first character of the key number sequence. This corresponds to a particular product code. For example, key number B19X 12345, with the letter B. is either product code 5247 or 5248. Each 16 mm product has a three­character designator, such as PXN, ECN, 291, etc. Above is a list of symbols for most Eastman motion picture film products prior to KEYKODE Numbers. For all films with KEYKODE Numbers, the product code appears as a four­digit product number, along with the emulsion and roll number on each strip of Eastman motion picture film (see KEYKODE Numbers charts). Please note that there may be more than one product with the same letter. If there is a question about a particular product, please contact one of the Eastman Kodak Company Offices. 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