Sampling 720 x 480 over an actual 320x240 full color picture.
320 x 2 = 640
240 x 2 =480
640 x 480 : 720 x 480 is over fit more than 2:1
Color Alone 160 x 120 : 720 x 480 is over fit more than 4:1
320x240 : 160x120 = Luma: Chroma
4:1 from 720 x 480 is a Perfect fit for full color capture
NTSC is field based so has more horizontal than vertical information per unit of time
"mixing" fields to "simulate" Progressive images is incorrect, artifacting is inevitable
DV is frame based storage it "does" compress the interlaced video into progressive frames.
4:1:1 more properly captures 100 percent of the Luma, Chroma and Temporal resolution without distortion
Even if capturing a theoretical 400 or 500 TVL, 720x480 is still over sampling and the increased resolution is in the Luma dimension, not the Chroma, bandwidth allocation is fixed.
(sencore)
720 x 480 DV 4:1:1 is still more than enough to capture everything available
The shape of the pixels captured for an NTSC signal are appropriate for the dimensions of the signal information available and skew more towards the horizontal dimension where there is more information.
The shape of the pixels captured for an ATSC signal are appropriate for the dimensions of the signal information available and skew more towards the vertical dimension to encompass the change in format from interlaced to progressive.
4:1:1 DV is appropriate for 4:3 Aspect and 720x480 digital capture
4:2:0 HDV is appropriate for 16:9 Aspect and 1280 x 720 digital capture
in plain simple language, DV video is appropriate for NTSC 4:3 video capture
in plain simple language HDV video is appropriate for NTSC 16:9 video capture
there is a "Reason" why these standards were developed, they are "overfit" for their purpose
While "live" Broadcast can in theory exceed what can be stored on Video tape in many cases, most of that available on VHS never stored the maximum available and it is already lost.
