SVHS
Like VHS, the S-VHS format uses a "color under" modulation scheme. S-VHS improves luminance resolution by boosting the luminance carrier from 3 MHz to 5.4 MHz. This produces a 60% improvement in (luminance) picture detail, or a horizontal resolution of 420 lines per picture height versus VHS's 240 lines. The often quoted horizontal resolution of "over 400" means S-VHS captures greater picture detail than even analog (NTSC) cable broadcast TV, which is limited to about 330 lines. In practice, when time shifting TV programs on S-VHS equipment, the improvement over VHS is quite noticeable. Yet, the trained eye can easily spot the difference between live broadcast TV and a S-VHS recording of it. This is explained by S-VHS's failure to improve other key aspects of the video signal, especially the chroma signal. In VHS, the chroma carrier is both severely bandlimited and rather noisy, a limitation that S-VHS does not address. To be fair, poor color resolution was a deficiency shared by S-VHS's contemporaries (Hi8, ED-Beta.), all of which were limited to 0.4 megahertz or 30 lines resolution.