An amazing DV camera
An amazing DV camera
JAKARTA (JP): DV is a high-resolution digital video format that gives exceptional quality. A key difference between DV and other video formats is that the information is stored as digital data. But, digital video is not necessary DV. DV is digital video but with a video format which is compressed. Any video that is digitized becomes digital video but it is not DV unless it is compressed with a DV codec. The DV format is a commonly agreed on specification for digital "domestic" camcorder format, which will eventually replace VHS-C, SVHS-C, 8 mm and Hi8 formats.
Agreed upon in 1993, 55 camcorder manufacturers support the format and will release camcorders in time. Two cassette sizes are specified: Standard four hour (125x78x14.6 mm) and a mini cassette (66x48x12 mm -- similar to a DAT tape). DV has specifications for both 12-bit (32 KHz) and 16-bit (DAT quality but 48 KHz) audio and has up to four 12-bit audio channels. Frequency response at 16-bit is up to 24 KHz and at 12-bit to 16 KHz. Manufacturers can choose which they implement.
A DV camera (a camcorder, or in Indonesia known better as handycam) is like Digital 8 (video format by Sony that can record video and audio digitally but still play analog 8mm and Hi8 cassettes) camera; it uses the "4:1:1" format for color recording. This captures three times as much color information as analog recording, which means better color intensity and accuracy.
DV cameras use the same code/decode algorithm as the Digital 8. The result is a gentle 5:1 compression and a 25-Mbps signal. MiniDV systems have a track pitch (spacing) of 10 microns and no control track, making linear editing difficult. For comparison purposes, VHS uses a 58-micron track pitch and 8mm uses 20.5 microns. DV uses a helical scanning recording head rotating at 9000 rpm (as opposed to 1800 rpm) and records to a Metal Evaporated tape (the same as Hi8 uses).
Standard features of a camcorder are optical and electronic zoom, a color LCD viewfinder, a lens, a steady shot, optical image stabilization and adjustable shutter speeds, and output for digital video and audio. Most users currently use the S Video output for nonlinear editing, with excellent results. For its power, a DVC use lithium ion batteries for longer battery life. It powers the camera for about an hour's usage.
DV cameras can tor record 12-bit audio (compared with 16-bit for CD and most nonlinear systems). Some DV cameras offer a "progressive scan" feature. This records each frame as a single noninterlaced image, instead of two separate interlaced fields. Progressive scan source material often does npt play as smoothly on television as interlaced material, but is vastly superior for desktop delivery because it contains no interlacing artifacts. You should look for this feature when buying a DV camera and use it when filming for desktop delivery.
Many people purchased a DV camcorder as a "disposable" (for shooting where the camera is at direct risk), or as a second unit and have been surprised by the results. DV has spawned two professional variations of the format with backward compatibility to DV -- DVCPRO from Panasonic and DVCAM from Sony. Both professional variants offer some advantages in edit capability but no fundamental change in picture quality.
However, as the camcorders released will, generally, be based on professional standard chassis and use professional quality (removable) lenses, the image quality is somewhat higher. Variations to the digital compressors used may also give quality variations between brands and subformats. (Gatot)