Professional mastering format from Panasonic.
D5 is a common mastering format for high definition post production. D5 started of as a standard definition format and some older VTRs do not have high definition capabilities.
This robust format is popular for several reasons. The 4:2:2 color sampling, 10 bit recording and relatively mild compression ratio of 4:1 are convincing arguments. The format also supports 8 channels of audio allowing for 5.1 and stereo composite audio delivery.
D5 covers virtually all commonly used HD standards in both 720 and 1080 frame sizes.