line numbers correspond to the real lines of the video frame. On all other systems, the field was considered to start with the falling edge of the first field pulse which gave the confusing position that the odd field (first) had a half a line of video occupying the latter half of a whole line and ended with a whole line of video but half a scanning line (and vice versa for the even field). The NTSC convention solved this confusion. For DV-NTSC only 480 lines are used. The digitally transmitted horizontal resolution is usually 720 samples (which includes 16 samples for the horizontal sync and horizontal blanking) or 704 visible pixels with an aspect ratio of 4:3 (with vertically rectangular pixels) and therefore a display resolution of 640 × 480 (VGA); that is standard-definition television (SDTV) with a 4:3 aspect ratio (with square pixels). The field rate (not the frame rate) is usually (60/1.001) = 59.94 hertz for color TV and is often incorrectly rounded up to 60 Hz. There are several conventions for written shorthands for the combination of resolution and rate: 480i60, 480i/30 (EBU/SMPTE always use frame rate to specify interlaced formats) and 480/60i. 480i is usually used in countries that conventionally use NTSC (most of the Americas and Japan), because the 525 transmitted lines at 60 hertz of analogue NTSC contain 480 visible ones. In each case of the use of the ‘60’ terminology, it is merely shorthand for 59.94, to differentiate it from 30 (29.97) or 24 (23.976). Color information is stored using the YCbCr color space (different from NTSC that used YIQ) with 4:2:2 sampling (also different from NTSC) and following Rec. 601 colorimetry. 480i can be transported by all major digital television formats (ATSC, DVB and ISDB) and on DVD. See also Enhanced-definition television (EDTV) List of common resolutions 4320p, 2160p, 1080p, 1080i, 720p, 576p, 576i, 480p, 360p, 240p References Television terminology Video formats