Kodak, Fuji and Ilford. Today Super 8 color negative film is the main color stock used. There are also Super 8 reversal films available, including 100D Kodak Ektachrome and 200D Agfa color, as well as black-and-white (B&W) from Foma, ADOX and ORWO and Kodak. The Super 8 plastic cartridge is probably the fastest loading film system ever developed, as it can be loaded into the Super 8 camera in less than two seconds without the need to directly thread or touch the film. In addition, coded notches cut into the Super 8 film cartridge exterior allow the camera to recognize the film speed automatically. Not all cameras can read all the notches correctly, however, and there is some debate about which notches actually deliver the best results. Canon keeps an exhaustive list of their Super 8 cameras with detailed specifications on what film speeds can be used with their cameras. Usually, testing one cartridge of film can help handle any uncertainty a filmmaker may have about how well their Super 8 camera reads different film stocks. Color stocks were originally available only in tungsten (3400 K) Type A, and almost all Super 8 cameras come with a switchable daylight filter built in, allowing for both indoor and outdoor shooting. The original Super 8 film release was a silent system only, but in 1973 a sound on film version was released. The film with sound had a magnetic soundtrack and came in larger cartridges than the original cartridge in order to accommodate the sound recording head in the film path. Sound film requires a longer film path (for smoothing the film movement before it reaches the recording head) and a second aperture for the recording head. Sound cameras are compatible with silent cartridges, but not conversely. Sound film is typically filmed at a speed of 18 or 24 frames per second. Kodak discontinued the production of Super 8 sound film in 1997, citing environmental regulations as the reason. The adhesive used to bond the magnetic track to the film is environmentally hazardous. In 2005 Kodak announced the discontinuation of their most popular stock Kodachrome due to the decline of facilities equipped with K-14 process. Kodachrome was "replaced" by a new ISO 64 Ektachrome, which uses the simpler E-6 process. The last roll of Kodachrome was processed on January 18, 2011, (although announced last date of processing was December 30, 2010) in