Getting the most out of your Arriflex or "Why should I have my camera serviced, it runs fine?”
To get the best image quality possible and to keep your camera running trouble free; the four reasons to have your camera serviced are:
The Arriflex 16S and 16M cameras are professional, production motion picture cameras but unlike their newer counterparts, which are designed to run "dry", the Arriflex 16S and 16M cameras are designed to run "wet".
The main drive gears in an Arriflex 16S and 16M cameras are a fiber composite and need to be well greased to prevent wear.
The feed and take up spindles, along with the drive and sprocket shafts of the cameras are polished steel in bronze oiled bushings. These bushings need to be kept well lubricated (but not over lubricated) with ARRI's specially formulated Chronosynth oil.
There are a number of ball bearings in the movement portion of the camera which must be kept clean and greased along with the special sapphire bushing on the registration pin movement which rides in a nylon cam.
An Arriflex 16S or 16M camera should be Cleaned, Lubricated and Adjusted (CLA) every two to three years if it's getting regular use and at least every four years if it is not being used. Otherwise the lubricants dry up and running the camera may cause severe internal damage.
The Flange Focal Distance (FFD) is the distance from the lens flange (that the lens seats against), to the film plane of the camera.
This is set at the factory to a tolerance of plus or minus 5 thousandths of a millimeter, which is equivalent to one tenth the diameter of a human hair. If the camera is dropped or sharply bumped, or the aluminum on the lens sockets is worn, this can cause the FFD to be out of spec. If the FFD is out of spec, the image the lens projects on the film plane will be out of focus. This is especially noticeable on wider angled lenses. For sharp, consistent images the FFD must be set to factory tolerances and the Ground Glass must be optically adjusted to match the FFD.
After the FFD is set on the camera the Ground Glass must be optically adjusted to match the FFD with the same tightness of tolerance. This assures that a sharp image on the Ground Glass in the viewfinder will be a sharp image on the film at the film plane. The Ground Glass must be optically adjusted to exactly match the FFD so that what you see in the viewfinder is what you get on the film.
The Arriflex 16S and 16M cameras have registration pin movement. What does a registration pin do? It's a common misconception that a registration pin is designed to enter the film sprocket hole and hold the film steady during exposure.
The registration pin actually works in tandem with the pulldown claw in what's referred to as Movement Timing. After each exposure, the shutter closes, the registration pin withdraws from the "locating" film sprocket hole, the pulldown claw enters another film sprocket hole and advances the film one frame. As the pulldown claw reaches the end of its travel, the registration pin starts to enter the new "locating" film sprocket hole and as it enters this hole it very slightly advances (registers) the film to a very precise point at which time the shutter opens and exposes the frame. Then the process repeats. The registration pin makes sure that each frame is located in exactly the same position on the film for each exposure, thus assuring a steady image that does not jump or move up and down when viewed at 24 frames per second. This is set very accurately at the factory but as the camera is used (and wear accumulates) the movement timing needs to be reset to the precise factory specifications to assure a steady image.
A Side Pressure Rail in the film channel exerts pressure on one side of the film to keep it running against a fixed rail on the other side of the film channel. This keeps the film from moving side to side as it's being exposed, thus assuring the image does not weave when viewed at 24 frames per second. The tension on this rail must be to factory spec, if it's too tight the film can jam, if it's too loose, the film can weave. As the camera is used (and wear accumulates) the center of this rail tends to bow out and needs to be straightened and reset to the factory specifications.
To obtain high quality images from your Arriflex 16S, 16S/B or 16M you need to have your camera cleaned, lubricated and adjusted to factory specs by an ARRI trained technician.