What is the difference between NTSC, 1080i, 720p and native?
To understand this we must have a basic understanding of how the NTSC system works. The following explanation is a generalization, for the enthusiast looking for all the details there are several good web sites which explain the complete operation of NTSC television. The NTSC system shows us 30 picture frames-per-second (fps) using two fields. Each field consists of half the scanning lines of the frame. Thus, in the first 1/60 second the television tubes illuminate odd numbered scanning lines 1-525 (there are always 525 vertical lines, horizontal resolution is the term often used to describe the sharpness of a TV set in “lines of resolution”). In the second 1/60 second the picture tube illuminates the even lines (2-524). these two fields of scanning lines are therefore interlaced at a frequency of 15750Hz. All of this is keyed to the power line frequency (60Hz) – in Europe the televisions are keyed to 50Hz. The “i” in 1080i stands “for interlaced” which means the picture is constructed
