For those of you who are not very familiar with Adobe Premiere or the Film Matchback problem, there are several points that you should understand before tackling the subject:
• Keycode numbers taken from the bar-code reference in the edge of all film negative done today are an exact reference to the edge numbers that are imbedded on the film stock 16-frames per 35mm foot and 20-frames per 16mm foot. At the moment of the film transfer to video they are burned-in over the video image, usually in the bottom-right side of the frame, to be used as a guide for cutting the original film negative after the film has been edited on a non-linear editing system. Keycode does not generate an audible signal for reproduction on other machines like it does for SMPTE Timecode, so the only reference to the original Keycode is the burned-in information found on the videotape generated by the transfer method.
• SMPTE Timecode is also generated at the moment of the film transfer to tape and is usually recorded on the bottom-left side of the frame. Since this is an audible tone recorded on a special track on the tape, it is used as a method to reference back to the Keyframes that it is in parallel and is the method used by different manufacturers of Keycode-generating equipment like Evertz Microsystems to generate a floppy-disk with all of the pertinent information for almost-perfect synchronization of Timecode/Keycode while using a system like the Avid Film Composer to do film matchback.
• Unfortunately Adobe Premiere does not include in its software the function of reading an Evertz-generated floppy disk, so we have to resort to other less sophisticated methods for doing a film matchback, which is the reason for this article. The following information which has been compiled after doing several professional jobs and experimenting long hours with the program to arrive at the suggestions which we are posting here, should in no way be taken as a final ideal procedure due to the many intricacies and pitfalls that are generated by the restrictions that are imposed by the «not-so-perfect» NTSC video standard.
• Since normal NTSC video runs at 30 frames per second (with two video fields per frame), the 24 frames generated by a film project have to be “expanded” to 30 frames to conform to the standard. In a normal telecine projector this is done easily by replacing the 4-sided shutter in the projection plate with a 5-sided one, which permits 5 frames to be created for every 4 projected. This obviously creates the necessary additional 6 frames-per-second necessary for the 30-frame NTSC standard. No problem here. But the real “standard” for transfering film to videotape is usually the Rank Cintel telecine which uses a system called the 3:2 Pulldown which creates two fields from one frame, then three fields from the next, then two again, and so on, creating the necessary 30fps/60fields second that we see on videotape. Fortunately, upon transfering your material with the appropriate video card into Premiere, the two video fields are eliminated and we’re back again to the normal 30-frame NTSC video standard. But in this conversion we’re losing 50% of the fields created by the Rank Cintel transfer. Visually this doesn’t affect us very much, but in terms of the film matchback, it does. When the 3:2 Pulldown scheme is used, the Keycode numbers created follow a regular 2-3 pattern and each number has an appropriate A,B,C or D letter following the individual frame (when it falls on a “real” frame) and B and C underlined letters for those that are duplicate or virtual frames. Of course, there are a lot of virtual frames with A,B,C and D markings, but most of them are lost in the digitizing process and in Premiere. In the 24-frame Premiere Project Preset the program simply eliminates every 5th frame of video in the normal 30 fps. transfer material. This is done indiscriminately beginning with the third frame from the start of each individual clip that is in the project or when you select the 24-frame option in the Clip Window Options.
Of course, by following this simple process, Premiere is automatically eliminating 36 fields from the 60-fields of transfer, thereby destroying all the purpose of the 3:2 pulldown scheme markings, making it difficult to sort out the real frames from the duplicates. We’ll discuss how to fix this further on. Now let’s start from the beginning:
The Transfer Process
First of all, get a good transfer from your post house and make sure that they give you very good (meaning, large and readable) burned-in Time Code and Keycode numbers, well within the safety-viewing limits. Your eyes will thank you for this.
Record your transferred footage on a format that you can easily use at home or in the office, like VHS. The added quality of Betacam SP or whatever will only cause you problems and a lot of extra dollars if you don’t normally use that sort of equipment and have to rent out.
Digitizing Your Material
When digitizing your material use a good I/O video card that gives you exact information about dropped frames. I use the Matrox Rainbow Runner which is about as inexpensive as you can get, but which gives you dropped frames read-outs and has excellent quality even in the lowest resolutions. Getting your material into your computer without dropped frames is an absolute must for your negative matchback. If possible (and if you can identify them), jot down your camera roll numbers at the moment of giving your clips a title. For example: Roll 006-Girl on Swing.avi.
Recording Timecode on Your Material
Once you have all of your material in the computer perfectly labeled and ready to go, open your Premiere 4.2 program and use any of the 30fps Project Presets to start your first ppj. Import all of your clips into the project bin and start with what is initially a very boring, but useful task: double-click on each of your scenes and open the Clip Window and select the Clip pull-down menu where you will find Timecode near the middle of the list. Click on it and write the exact timecode numbers of the first frame of each clip: 30fps, Non-drop Frame, File Beginning and the number of the reel that the clip belongs to. Even though this information is not absolutely indispensable for the success of your film matchback it does provide you with (a) an EDL readout, (b) gives you a «second reading» for comparing the length of your shots and (c) gives you an easy method to check if you have any dropped frames (if you go to the tail of the clip and the numbers on screen aren’t absolutely identical to the Premiere read-out, you’re missing frames somewhere). The information that you record at this moment will become an integral part of that clip wherever you take it within Premiere, so you only fill it in once and that’s all.
The Final Edit
After you have done all of this, you can start a New Project with the 24fps Project Presets this time. From here on you can do all of your editing without worrying about anything else until you have what you consider your absolute final cut and you’re ready to tackle the Keycode problem and your negative matcher. Up to this point this can be a process of days, weeks or months, depending on your project. You must be totally certain that what you’ve edited is what you want to see exactly on the movie screen and that you’ve taken care not to duplicate shots or intercut scenes without keeping in mind the frames which will be lost in the splicing process of film matching and preparation for final printing. As is usual in film work, make a 1-frame beep signal in the sound track (use the 1khz_snd.aif sound tone from the Goodies section in Premiere) exactly 48-frames (2 seconds) before the first frame of picture and follow the same procedure in the tail end of your project so that you can have two perfect sync marks for checking your sound track to your picture.
Render and Re-Name Clips