NTSC DV = 720x480 NTSC D1 = 720x486 (both at 29.97 fps) NTSC Square pixel is 750x540 PAL D1/DV is 720x576 at 25 fps PAL Square pixel is 786x576 You would use square pixels if your editing app doesn't support non-square pixel ratios (for ex., Premiere 5 DOES NOT support non-square pixels, Premiere 6 DOES), or if you were creating still images for import. Video CD has several different formats and resolutions that you should research before beginning your project. Many set-top DVD players are not compatible with all of the VCD formats.