S-VHS (スーパー・ヴィエイチエス), the common initialism for Super VHS, is an improved version of the VHS standard for consumer-level video recording. Victor Company of Japan introduced S-VHS in Japan in April 1987 with their JVC-branded HR-S7000 VCR, and in certain overseas markets soon afterward.
Like VHS, the S-VHS format uses a color under a modulation scheme. S-VHS improves luminance (luma) resolution by increasing luminance bandwidth. Increased bandwidth is possible because of increased luminance carrier from 3.4 megahertz (MHz) to 5.4 MHz. Increased luminance bandwidth produces a 60% improvement in (luminance) picture detail, or a horizontal resolution of 420 vertical 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 NTSC analog cable and broadcast TV, which is limited to about 330 television lines (TVL). 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 television and an S-VHS recording of it. This is because S-VHS does not improve other key aspects of the video signal, particularly the chrominance (chroma) signal. In VHS, the chroma carrier is both severely bandlimited and rather noisy, a limitation that S-VHS does not address. The poor color resolution was a deficiency shared by S-VHS's contemporaries, such as Hi8 and ED-Beta – all of which were limited to 0.4 megahertz or 30 TVL resolution.
Regarding audio recording, S-VHS retains VHS's conventional linear (baseband) and high fidelity (Hi-Fi) – Audio Frequency Modulation (AFM) soundtracks. Some professional S-VHS decks can record a pulse-code modulation (PCM) digital audio track (stereo 48 kHz), along with the normal video and Hi-Fi stereo and mono analog audio.
As an added bonus, due to the increased bandwidth of S-VHS, Teletext data (PAL) signals can be recorded along with the normal video signal. As a result, this Teletext data is also able to be decoded and displayed on-screen as an overlay of the conventional TV picture (though not on standard VHS machines). A suitably Teletext-equipped receiver/decoder (TV, PC card, etc.) displays the recorded Teletext data information as if the video were being viewed as a real-time live broadcast.