Digital 8
 

8

Digital8 (or D8) is a consumer digital videotape format developed by Sony, and introduced in 1999.

The Digital8 format is a combination of the older Hi8 tape transport with the DV codec. Digital8 equipment uses the same videocassettes asanalog Hi8 equipment, but differs in that the audio/video signal is encoded digitally (using the industry-standard DV codec.) Since Digital8 uses the DV codec, it has identical audio and video specifications.

To facilitate digital recording on existing Hi8 videocassettes the video head drum spins 2.5x faster. For both NTSC and PAL Digital8 equipment, a standard-length 120-minute NTSC/90-minute PAL Hi8 cassette will store 60 minutes of Digital8 video (Standard Play) or 90 minutes (Long Play). LP is model specific, such as the TRV-30, TRV-40, and others. Digital8 recordings can be made on standard-grade Video8 cassettes, but this practice is discouraged in the Sony user manuals. Hi8 metal-particle cassettes are the recommended type for Digital8 recording, and most tapes currently sold are marked for both Hi8 and Digital8 usage.


 

MiniDV/DVC vs. Digital8

 

Contrary to popular perception, the Digital8 format is not technically inferior to miniDV -- both are identical at the bitstream level. From a user standpoint, Digital8 is DV (or rather, equivalent to and compatible with consumer miniDV.) At an application level (for example, in a 1394/Firewire link), a Digital8 camcorder appears and behaves exactly like a Mini DV camcorder.

Digital8 and Mini DV use different, non-interchangeable cassette media, with Digital8 cassettes being the physically larger of the two. The two formats may also use different media formulations: Digital8 can use metal-particle or metal-evaporated media, while miniDV is based solely on metal-evaporated media. The maximum recording time for Digital8 and MiniDV is 135 minutes and 130 minutes, respectively, using D-90 and DVM-85 tapes. These extra-thin, extra-long tapes are rare and expensive. [[1]] [[2]] [[3]]

In addition, Digital8 uses tape at 29mm per second; more like the higher-end DVCAM (28mm/s) and DVCPRO (34mm/s). MiniDV uses tape at 19mm/s. According to Sony's press release of January 7, 1999, for the MiniDV format one frame is recorded onto 10.0 tracks, with the Digital8 format one frame's worth of information is recorded vertically onto 25 tracks. The use of this recording method enables digital images to be recorded on a Hi8 tape.

Another area Digital8 cameras excelled over the MiniDV cameras is their optical zoom. Digital8 cameras range from 15x and 25x optical zoom while MiniDV cameras of the same year and market segment were between 10x and 12x, with some topping out at 15x. This changed in the following years as some MiniDV cameras such as the DCR-HC38 have an optical zoom of 40X.