Type C videotape

1 inch C ( also 1 " C ) was a video tape format that was developed in 1976 by Ampex and Sony and introduced in 1978.

It used a 1 inch wide magnetic tape and replaced in the field of professional video and television industry which was then established quadruplex format ( colloquially known mostly 2 inch Quad, in the literature 2 inch Quadruplex ) because it was not only smaller and lighter, but also had a slightly better video quality and less maintenance, energy and space needed. Experience from other tape formats such as the 1 inch and 1 inch A B systems, as well as the relatively young U-matic went without doubt one with.

1 inch C- machines are no longer built by the early 90s.

The recording

It captures a composite signal which is recorded in the direct FM method. It can be recorded four longitudinal audio channels, but the machine usually allowed only the inclusion of three tracks, as the fourth track is used as a sync track. The third track can be used to record the LTC time code according to EBU / SMPTE, also is in the image track of VITC recordable.

Technical specifications

The video bandwidth = Sharpness ( more precisely, resolution) ranges from 25 Hz to 5.5 MHz, a specification that was only in 1986 reached again from BetacamSP system. The speed of the belt was almost 24 cm / s, / s corresponds to a relative velocity of 21.4 m. There were two reel sizes: 20 min. the small coil, 60 or 90 min later. the big one.

These machines, BVH series from Sony, are found exclusively in console cabinets again, because even for displaying the image on a monitor, a TBC (Time Base Corrector ) is mandatory by the drive very many inaccuracies in the pure signal, in addition to the MAZ are in such a console WaveFormer, a vectorscope (both in the top right next to the monitor to see ), installed a monitor and the TBC and usually a pair of speakers.

The TBC is installed under the machine in the console. The visible measuring instruments indicate the audio level (the three left ) and the video level ( right).

The tape is wound in an omega shape around the head drum from the position of these results in the machine, the corresponding symbol of the format.

Special cases

• A variant ( 3000 at the latest generation of devices, BVH series) was the threading of the tape with compressed air to prevent damage to the tape and the heads.
• For watching sports super motion has been developed - a way to 525 lines / 29.97 180/2 fields now record images with the NTSC area with the same number of lines.
• Delta t -recording was to establish a possibility recordings that differed from the normal tape speed, it was possible to record still images, gradually capturing still images at a fixed grid and slow motion record, this was a special type of so-called DT- heads (dynamic tracking to German: tracking ) causes.

Swell

• Jürgen Burghardt: Manual of the professional video recorder. edition movie workshop, Food 1994, pp. 447-455

• Videotape format