"Stupid question" may be close on target. Not trying to be funny but since your title talks about recording and your question says S-Video which generally refers to a method of video signal transmission. However, maybe I can briefly describe each recording process and you can pull enough info to answer your real question.
S-Video generally refers to Y/C video signals of a "component" video as in Luminance and Chrominance. It is most closely related to Hi8 or SVHS recording tape formats, but since it is just a way to convey video signals in the lowest form of component, it has been used to carry other video from other tape formats as well. eg. I have Y/C or "S-Video" I/O on my betacam SP recorders. Y/C video format is a color under or heterodyned video format using a color subcarrier for the color information. The subcarrier is at 3.58 Mhz.
When this color under video is recorded as in Hi8 or SVHS recording it is simply recorded as a "Composite" single track. Therefore there is no true maintaining of the Y/C components in the actual tape for Hi8 or SVHS. This is not so with true component recording, such as betacam where the components Y, R-Y, B-Y are recorded to two adjacent video tracks. One carries the Y, and the other carries both the R-Y and B-Y in a "C" track where these two signals are multiplexed. This is done with in such a way that it can be later separated into the two color difference components in a near perfect manner, resulting in the three discretely separate components on playback. No hetrodyning is used and the color purity is maintained.
So, with that understanding you can now examine the "bandwidth specs for the two different video tracks on tape.
In betacam SP:
Y- 4.5 Mhz
C1- 1.5 Mhz.
C2- 1.5 Mhz.
The chroma is 1.5 Mhz and the Y is 1.6 Mhz but at a center carrier freq. of 7.0 Mhz. The Y and C are combined as a color under video signal when recorded on tape.
Bottom line is you can't simply single out one measurement and make a comparison.
The same goes for comparing digital tape formats with analog, by using bandwidth. In some respects the bandwidth may be higher as in the case of DVCAM 5.5Mhz vs. Betacam 4.5Mhz but in the case of color information the sampling for DVCAM is less than the color bandwidth ratio for betacam.
The way I keep all this straight in my head is to simply compile all the performance plusses and minuses for each tape format and then know that for one recording purpose, this format is the best and for another purpose another format will be better.
Using my video production company as an example, I use DVCAM and Betacam SP. I know that for reliability, to get the shot, DVCAM is superior. It has much better dropout specs, better recording time, better audio noise floor, and slightly more saturated colors. However Betacam SP is better for industry wide compatibility, better for shooting footage for chroma keying, and produces less artifacting from compression during the edit process and has no aliasing on hard diagonals like DVCAM has. As a videographer, I prefer to evaluate all tape formats based on overall performance for the job at hand. As an engineer, I can sit and chart the numbers, but they mean squat in the real world of actual shooting and editing.
Now, the only thing "stupid" about your question is the idea that you can make a "bandwidth" comparison between your choices and have it mean anything significant and that's an engineering fact. In otherwords, its not the data that is stupid, its how one may interpret the data that is.
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Last updated 3/25/01