Edge Numbers and Film Footage
The laboratory produce a copy of the original for you to cut. Except in the case of rush television news filming, the original film exposed in the camera should never be used for cutting. It is too valuable.
Final stage of cutting
When you have finished the job and the edited version is perfected, you can match the original to the cutting copy. This is done by matching sets of numbers on the side of the cutting copy with identical numbers on the edge of the original film. The numbers are matched and, where the cutting copy has been cut, the original is cut too. When the two match exactly the original can be printed on a roll of new, unjoined stock, thus making a copy of the edited version free of dirt, wear and scratches.
Edge numbers
The numbers on the side of the film are known as edge numbers (or key numbers). When you receive the rushes from the laboratory the numbers are the first things to check. Check before you start cutting. The numbers are on the camera original but you must make sure that the laboratory has copied them on the print. It is quite possible to mask off edge numbers in a laboratory printing machine. So, check and make sure that they are present before you start work. The neg cutter will rely on those numbers to match the original to your cutting copy but if they are not there he will have difficulty matching your work print. The work will take longer and it will be much more expensive. If the numbers are not printed through on the copy, return the copy and the original, if you have it, to the laboratory and ask them to print edge numbers on both.
Film footage
Film is measured in feet. A foot of 16m. film consists of 40 individual frames separated by perforations. Edge numbers normally occur once in every foot, though on some recently introduced film stocks they are to be found once every 20 frames. The numbers are always different. If you look at a piece of 16mm film the edge numbers might be, say, JH 125833. If you now look forty (or occasionally at may be 20) frames further on you will find another number one digit higher: JH 125834. Forty (or 20) frames back in the other direction there will be another number one digit lower. When rushes arrive in a cutting room you must log the numbers of the rushes before they are cut or broken down.
EDGE NUMBERS AND FILM FOOTAGE
Also known as key numbers and footage numbers, edge numbers are incorporated in the film during manufacture. The numbers appear when an original is processed. On 16mm film there is normally one number every 40 frames or on some stocks one every 20 frames. On 35mm film there is one edge number every 16 frames.