User manual SONY HDV TECHNOLOGY BOOK

[. . . ] Contents worryfreedigitalTM video . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Toward worryfreedigitalTM High Definition video. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Arrival of the HDVTM Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HDV Advantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] That's why High Definition television uses a wider screen, with an aspect ratio of 16:9. This wider screen is 16/9 or 1. 778 times wider than it is high. In this way, the wider 16:9 screen is a better match for the human visual field. The result is an even more lifelike, more immersive experience--closer to the feeling of "being there. " 17 Standard Definition (left) uses a 4:3 aspect ratio that's almost square. High Definition (right) uses a 16:9 aspect ratio that's more panoramic--and closer to the actual field of human vision. HDV TECHNOLOGY HANDBOOK 4. Interlace and progressive scanning In video, what appears to be a continuously moving image is actually a series of discrete still pictures, called frames. In NTSC Standard Definition, each frame lasts 1/30 second and contains 480 effective scanning lines that appear on the screen. Because of limitations in the early days of television, these 480 lines were divided into two "fields, " each of which lasts 1/60 second. At the studio camera; the first field captures the odd-numbered scanning lines, skipping every other line. The second field comes back and captures the even-numbered scanning lines. This is "interlace" scanning and it displays only 240 scanning lines at any one time. Interlace scanning in the studio camera is mirrored by interlace scanning in the home television, for accurate display of motion. In PAL and SECAM countries, interlace works the same way, but the specific numbers are different. Each frame lasts for 1/25 second and includes 576 effective scanning lines. These are divided into fields that last 1/50 second and contain 288 scanning lines, each. Interlace scanning (right) displays the video frame in two fields, one for the odd-numbered scanning lines and one for the evens. 18 Interlace scanning (left) divides each frame into two fields. Progressive scanning (right) does not divide the frame. Depending on the country and the implementation, High Definition retains interlace scanning, but adds the additional option of "progressive scanning. " In the progressive system, every scanning line is shown in sequence. The video frames are not subdivided into fields. The 1080-line interlace High Definition system offers superior horizontal resolution. But because the interlace process sacrifices some clarity in the vertical direction, the 720-line progressive system has slightly better vertical resolution. With line rate, frame rate and scanning type all variable, special notation, such as "1080/60i" is used to describe each choice. This expression defines the picture as 1080 effective scanning lines, 60 fields per second with interlace scan. 5. [. . . ] The scan begins at the top left of the picture and moves in a horizontal line to the top right. Then the next line underneath is scanned and so on until the bottom of the picture. The horizontal lines traced in the scanning process. The more lines, the sharper the picture. [. . . ]