W-VHS vs Betacam

[roxics]

Just something I was thinking about. Betacam runs the tape at something like five to six times faster than traditional Beta in order to get 300 lines of video with 120 lines of component color. But you get a short runtime per tape as a result.
W-VHS on the other hand is able to give you two hours of standard VHS-like runtime but with an HD signal and also component color.

I learned from digital video that if you take a 1080p resolution 4:2:0 video you can get a 4:4:4 480p video out of it. I'm guessing analog video might work differently in that regard.

I guess my question is, would you be better off with W-VHS than Betacam if looking for both higher quality and longer record time, if hypothetically speaking, both had been available in 1982 when Betacam launched?

[Cornucopia]

You have got some numbers wrong.

Both are component analog signals.
Betacam (82) records (vertical resolution) exactly 525 iines NTSC or 625 lines PAL, and its signal is continuous. That means its limit of resolution is down to the filtering in the camera's & recorder's electronics. They say (in that wikipedia article) the "effective" horizontal resolution is 300 lines (with Beta SP being 340), but I can tell you from experience that it is more than that - more like 550-600.
The difference is that the limit used in those web calculations always refers to the 4.2MHz bandwidth limitation of BROADCAST NTSC. However, component recording formats do NOT have that limitation yet. They are UPSTREAM of the the transmitter (with a Luminance bandwidth of ~6.4MHz, IIRC), and since they are not (usually) "broadcasted" to their recorders, so the bandwidth being recorded is higher that what actually will end up going out via the TV transmitter. And the equivalent chrominance is ~5.7MHz, so also much higher than previously stated. All of that was limited by what the available cameras of the day were able to provide, which was often the limiting factor.

W-VHS has a number of improvements in technology due to being designed 11 years later, which Betacam doesn't have: higher density metal particle tape, time-compression integration allowing double data throughput, dual R/P heads allowing 2 tracks' worth of data to be stored simultaneously (doubling the throughput again), & advanced crosstalk cancellation. That, plus a higher speed than consumer VHS does allow for analog HD (1035/1125) to be recorded. However, it also cost ~ double what Beta/SP cost (recorder vs. recorder). That, plus the fact that it used the MUSE system which didn't catch on beyond Japan, also means that it wasn't near as compatible with existing systems (which were VERY predominantly still SD through the 90s).
W-VHS did have a record time of ~107 minutes vs. 31 minutes of Beta, but that is also not 120+ minutes either. But for pros (the only folks who were buying either of these devices) tape runtime was not a deciding factor. Also, Beta was designed for mobile acquisition. W-VHS was not.

There was a very good reason BetaSP was the king of analog SD, and it continued to be popular even well into the HD & Digital revolutions.

Apples vs Oranges.

Scott

[roxics]

Thank you so much for your feedback. That's all satisfying to my curiosity. I never worked with Betacam since I didn't get into video production professionally until the early 00s. Even then I was on the lower end of the market using DV/HDV at the time. But I remember these pro formats (not W-VHS) growing up in the 80s/90s.

I would assume there has to be an upper limit to Betacam as well though, aside from the cameras/decks used, since I assume the tapestock had a maximum signal limit it could hold. Even for really nice metal particle tape. But I don't know.

I was just curious if cost was no factor and both formats dropped into 1982 with both cams and decks available, which would have been preferred.

[Cornucopia]

Limit of BetaSP was like equivalent to 600x480/576, with ~50dB SNR.
None of the analog formats except Hi8, IIRC, used metal particle tape. Metal didn't really appear on analog videotape until late 80s (metal started in early/mid80s with analog audiotape first), and by that time of late 80s most of the other analog formats had been established. It did get used for a number of digital tape formats, though.

I am intimately familiar with Beta/SP and its pros and cons, but have only had sporadic use with W-VHS. My memory is that W-VHS didn't hold up as well with artifacts and with multiple generations. Remember, any time you incorporate some form of compression (be it digital bitrate reduction, analog dynamic range compression, or time domain compression), and anytime you decrease analog areal recording density & speed per bandwidth, you are making compromises and the signal is - for lack of a better term - more fragile. So, I would say BCSP was very robust, and WVHS less so, but both are head & shoulders above your consumer formats like vhs & betamax, and even Umatic.
Looking strictly at resolution, of course an HD signal has the lead over an SD signal. But those formats had other parameters to gauge them by, and I would say that it wasn't until digital hit its stride and digital compression went through a few generations, before HD (often in the form of HDCAM) was hands down 100% better all the time over SD, using all those metrics. That was around 2001/2002. So the safe bet in the 80s and early 90s would have been Beta, BetaSP.


Scott

[dellsam34]

Professionals usually go for a reliable and well supported format, Betacam delivered that. W-VHS was more of like IMAX for film, It wasn't built around mobility and speed, The camera's are oversized and are suitable for studio or steady shooting, Also the cost is another factor, Studios main goal is to get the news delivered, HD wasn't that important to them.

[roxics]

Limit of BetaSP was like equivalent to 600x480/576, with ~50dB SNR.
None of the analog formats except Hi8, IIRC, used metal particle tape. Metal didn't really appear on analog videotape until late 80s (metal started in early/mid80s with analog audiotape first), and by that time of late 80s most of the other analog formats had been established. It did get used for a number of digital tape formats, though.

I am intimately familiar with Beta/SP and its pros and cons, but have only had sporadic use with W-VHS. My memory is that W-VHS didn't hold up as well with artifacts and with multiple generations. Remember, any time you incorporate some form of compression (be it digital bitrate reduction, analog dynamic range compression, or time domain compression), and anytime you decrease analog areal recording density & speed per bandwidth, you are making compromises and the signal is - for lack of a better term - more fragile. So, I would say BCSP was very robust, and WVHS less so, but both are head & shoulders above your consumer formats like vhs & betamax, and even Umatic.
Looking strictly at resolution, of course an HD signal has the lead over an SD signal. But those formats had other parameters to gauge them by, and I would say that it wasn't until digital hit its stride and digital compression went through a few generations, before HD (often in the form of HDCAM) was hands down 100% better all the time over SD, using all those metrics. That was around 2001/2002. So the safe bet in the 80s and early 90s would have been Beta, BetaSP.


Scott

Again. Thank you for your reply. Super helpful.

It is interesting. If digital had taken longer, I wonder if we would have seen W-VHS or something like it mature into more of a professional analog HD system. I know Sony also had their HDVS.

I don't know if it's just nostalgia or what, having grown up with VHS, Video8, and to some degree Betamax, and Laserdisc, but I've become interested in the analog video formats again. My friends and I used to cut our teeth on VHS and Video8 camcorders shooting little stop motion animation movies and live action horror and comedy movies back in the 90s before I bought a TRV900 in 1999 and started shooting DV. So it reminds me of my youth. Of course back then I hated the look because it wasn't film. It didn't look like a proper movie but like a soap opera. These days I go out of my way to find old SoV (Shot-on-Video) movies from the 80s and 90s. Funny how perspective can change over time. Lol.

Just out of curiosity, kind of a stray thought since you brought up digital compression, but I wonder what the actual bitrate of VHS would be, if it had been digital back in 1977. I've heard estimates that a VHS tape could hold the digital equal of anywhere from 2GBs to 8GBs, with D-VHS tapes holding 50GBs. But they used higher end tape. I'm just talking straight 1977 VHS. I think knowing the digital capacity of that would give a better idea of the kind of bitrates a digital equivalent would be at different speed. Even if we are talking apples to oranges.

it's something I've been thinking about since I've been transferring some old VHS tapes to DVD these past couple days. I'm surprised at how good they look on my 55" 4K TV. I was expecting an absolute mess on the big screen. Granted they are being scaled up through my DVD-recorder and sent out of its HDMI port. But I've done tests in the past on my computer where I've converted DVDs to 352x480 resolution mp4s (just to see the results), and unless the bitrate is high enough like that of DVD, it's not looking anywhere near as good as the VHS tapes do on my big screen. They are blocky/pixelated versus the softer noisy VHS, which I think I prefer. It seems less distracting. But if you have to use bitrates as high as DVD to get rid of the pixelation, you might as well be using a full D1 resolution instead of half. It appears less pixelated it seems. So I can never seem to find a valid use for half D1. With that considered.
Anyway, like I said, just a stray thought.

[roxics]

Professionals usually go for a reliable and well supported format, Betacam delivered that. W-VHS was more of like IMAX for film, It wasn't built around mobility and speed, The camera's are oversized and are suitable for studio or steady shooting, Also the cost is another factor, Studios main goal is to get the news delivered, HD wasn't that important to them.

Yeah I can definitely understand that.

[Cornucopia]

I think you are seeing it through the lens of nostalgia.

VHS & Beta and V8 was, and is, for lack of a better term, poor. I won't say crap (although looking at 3rd gen home-recorded SLP, is could very well be). Those consumer formats never even achieved the capability that SD was capable of (C-format & Laserdisc being the best composite analog versions and Betacam/SP & MII being the best component analog versions, and D2 and D1 being the best uncompressed digital versions respectively).

The problem with digital has always been HOW MUCH BITRATE IS GOOD ENOUGH? (good enough for WHO?, WHEN?) And back when digital consumer video formats were just getting popular (late 90s, early 2000s), what was "good enough" then is embarrassingly mediocre today. So many folks undercut themselves in the name of small size/quick transfer that those old digital copies with their excessive artifacts don't hold up as well, in fact even as well as standard analog degradation does. Folks here were/are guilty of it all the time, even in today's streaming-heavy era.

But I for one have little nostalgia for either of those - my bar is high and I want the best, regardless of format, so it's a little easier to be objective when evaluating.
Here's an example that I've mentioned on this forum before: guitar virtuoso Ry Cooder's "Bop Til you Drop" album came out in 1979, and it had the notoriety of being one of the first non-classical albums that was full D-D-D recording chain. And though the digital technology wasn't even as good then as it will have been a few years, or decades, later, the engineers were adamant at getting the best possible quality out of it, and made sure to eek out every bit of dynamic range available while maintaining proper dithered processes all along the way. And it shows - listen to "The Very Thing that Makes Her Rich (will make you Poor)". I describe it as "silky" and "scintillating", with NO background hiss, just the "natural" studio-produced reverb. And well produced analog recordings of that era simply did NOT sound anywhere near to what this did. Which is why digital recording exploded in the ensuing era.
Now, I've heard this recording on multiple formats - original LP, FM radio, cassette, CD, mp3, SACD, streaming (Spotify/aac). It's easy to order the quality: 1st is SACD, then CD (superbitmapped), regular CD, LP, aac, mp3, FM radio, cassette. Notice how both analog & digital are in the mix, but well-crafted digital still is top dog.

The same can be said on the video side of the difference between (well-produced) VHS, vs D1 or even DVD. When factors of inadequate efforts & production choices are factored out...it's not even close. I would go hands down with DVD (since I have almost no access to true D1 material any more) every time. That doesn't even take into consideration the extra features and the convenience factor.

I'm not going to dwell much on "what if"'s with regard to bitrates expected of vhs. If you want to get a reasonable guess, you could look at what LTO and similar data backup tapes have been throughout the years (since it happens to also be 1/2" magnetic tape). Not counting its many precursors of lower capability, when LTO1 came out in 2000, it read/wrote ~160mb/sec with a total of 100GB per tape. VHS in comparision had a much slower tape speed but countered that with the helical scanning, so it probably was equivalent, and would likely not have the advanced track-writing capability that LTO had, and while LTO tapes were 607meters, your usual T-120vhs tape was 247 meters, so 2/5 the size, making that equivalent to ~40GB. That's using 2000-era technology, not 1976 era. That's about as much as I am going to speculate.


Scott

[roxics]

Thanks again for your reply. It's very helpful. It's all very interesting to me.
I too generally prefer the newer higher quality stuff. But I do get nostalgic for the old as well. Now that things can be perfect I think there is character in imperfection. Like an old comfortable worn-in leather jacket. There is a quote by Brian Eno that I think fits:

“Whatever you find weird, ugly, or nasty about a medium will surely become its signature,” writes Brian Eno in his published diary A Year with Swollen Appendices. “CD distortion, the jitteriness of digital video, the crap sound of 8‑bit — all these will be cherished as soon as they can be avoided.” Eno wrote that in 1995, when digital audio and video were still cutting-edge enough to look, sound, and feel not quite right yet. But when DVD players hit the market not long thereafter, making it possible to watch movies in flawless digital clarity, few consumers with the means hesitated to make the switch from VHS. Could any of them have imagined that we’d one day look back on those chunky tapes and their wobbly, muddy images with fondness?

https://www.openculture.com/2019/10/the-beauty-of-degraded-art.html

As for VHS, you said:

while LTO tapes were 607meters, your usual T-120vhs tape was 247 meters, so 2/5 the size, making that equivalent to ~40GB. That's using 2000-era technology, not 1976 era. That's about as much as I am going to speculate.

That seems to line up pretty well with D-VHS at 50GBs per tape in the late 90s. So that sounds about right for that era.

I did once hear (I forget where) that RCA CED discs were about 1GB of capacity (had they been digital). I also don't know if that's considering the entire disc or just one side, I assume single side. But CED is about the quality of VHS. So it's possible that VHS in that era was closer to 1GB. I've already read Laserdisc was around 4GB (single side), but it was also higher quality than VHS in horizontal resolution and color. So again, 1GB (to maybe 2GBs) for VHS does start to sound right for 1977 era tech. But I'm just speculating.
Just for fun though, I wonder if something like late 90s era magnetic Zip disks with 750MB capacity could be configured to store around 90 minutes of VHS quality analog video. Might have been interesting if that tech had existed in the 70s and VHS had been a magnetic disc format like a Zip disk instead of a tape cassette. Just something I was thinking about. Again, for fun.

[Cornucopia]

Rather than wild speculation, try looking at what the state of the art actually produced during that time:
During the 80s and up through the mid 90s, the common master format for sending digital audio to the factory to be pressed into (audio) compact discs was onto 60minute large 3/4" Umatic video tapes, encoded solely audio, using the Sony PCM-1600 and similar encoders.
Aka digital audio encoded as analog video & analog video decoded as digital audio.

Using a calculator: 60 (minutes) * 60 (seconds/min) * 44056 (samples/ch/sec) * 16 (bits/ch) * 2 (ch) / 8 (Bytes/bit) / 1024 (kiloBytes/Byte) / 1024 (MegaBytes/kiloByte) = 60 * 60 * 44056 * 16 * 2 / 8 / 1024 / 1024 = 605 MB. That was the limit in the early 80s - longer CDs could be created, but required multiple tapes. Vhs & Beta were not considered robust enough (sufficient bandwidth, SNR) to use (although some hobbyists did attempt this with their personal collections, and using the later PCM-F1 encoder).

For technical, compatibility (of NTSC vs PAL) reasons, 44056 Hz was used instead of 44100. This was fixed on workstations at the pressing factory (and usually pre-compensated for in the studio).


Scott

[roxics]

So wasn't Umatic basically equal to beta(max) just using 3/4" tape? Which was also close to VHS. Better but close.
So if I'm reading you right, then a 60 minute Umatic (beta/VHS) tape would yield 605MBs which means a two hour tape would be roughly 1.2GBs. Basically around the 1-2GB being speculated. Which is also around the same as CED is speculated to have, which is similar in quality. So that kind of all lines up. Unless I'm wrong somewhere.

[Cornucopia]

No.

Not sure why you are equating -
3/4" tape running at 9.53cm/sec, ~47dB SNR, Y-C (luma, chroma fully separate), ~250-300-330 horiz lines of effective resolution
with
1/2" tape running at 3.335(NTSC) or 2.339(PAL) cm/sec, ~45dB SNR, color under (luma, chroma together, then separated), ~240-250 horiz lines of effective rez.

It is said that because of logarithmic scale, with every ~3dB of video SNR, it is similar to a 10x improvement in perceived quality (making the extra 2dB of Umatic modestly but noticeably above the consumer formats).
In analog formats, anytime that you have an increase in tape width, there is an increase in fidelity & SNR. And anytime you have an increase in (relative/effective) tape speed, you have an increase in bandwidth.
U-matic (even the non-SP variety) had VHS & Betamax beat on both these counts. It wasn't until S-VHS and EdBeta arrived that there was comparative quality (and those were only gotten by incorporating technological advances gathered in the interim). The increase in recording length always occurred only to satisfy consumer convenience needs, not quality.

If VHS & Beta can do much longer lengths, but only because they run at such slower speeds, the density of the tape (aka magnetic regions) running past the heads is much lower. When that happens, less can be captured, nor more, independent of the "total length".

BTW, CED was *CRAP*, having seen demos in their day, as well as having some "rentables" at the video store I managed. Laserdisc was in another league.

Regardless, NONE of these formats were exemplary. Certainly not as archival masters

Note: the figures I quoted earlier about the digital audio encoders were just a general reference. In a sense, they use sections of the scanline and so would be considered duplicative of modern scanning & digitization methods, but then again, they also are incorporating error correction directly into the scanned signal (which modern methods do distinctly differently), which accounts for some of the duplication overhead.

You've moved quite far afield from the topic of W-VHS, which was never a common format in North America to begin with, and has been addressed. It feels like you are just grabbing at nostalgia now to justify continuing the thread with varied "what if"s, or perhaps this is just amused trolling?



Scott

[roxics]

No.

Not sure why you are equating -
3/4" tape running at 9.53cm/sec, ~47dB SNR, Y-C (luma, chroma fully separate), ~250-300-330 horiz lines of effective resolution
with
1/2" tape running at 3.335(NTSC) or 2.339(PAL) cm/sec, ~45dB SNR, color under (luma, chroma together, then separated), ~240-250 horiz lines of effective rez.

Ok gotcha. I made the correlation based just on a base resolution of around 250 lines for all three (four actually - including CED at around 240-250 lines). For some reason I was under the impression that Umatic was basically Sony's first attempt at Beta(max) using larger tape, since it came out earlier. That it got a foothold in the corporate/lower end ENG market due to cost and early adoption. I didn't realize it was a superior format and that was the reason it kept being used. I just figured that within a few years Sony had figured out how to improve the technology enough to write the same signal to a 1/2" tape that had previously required a 3/4" tape. But it makes sense it was higher quality, with the bigger tape equalling more area for more bandwidth.

You've moved quite far afield from the topic of W-VHS, which was never a common format in North America to begin with, and has been addressed. It feels like you are just grabbing at nostalgia now to justify continuing the thread with varied "what if"s, or perhaps this is just amused trolling?

Sorry about that. The truth is you're a wealth of knowledge on this subject. So even when I get something wrong (which is quite a bit), your responses are like a masterclass in video tech, which I am extremely appreciative of. So I've learned a lot in this whole thread, even veering off the initial subject.

I had started this thread based on an idea I had in my head. A hypothetical/speculative question of "what would be the best analog video format to drop in 1982(from any time) that could work for both consumers and potentially professionals alike?"
It had occurred to me that W-VHS was both higher resolution and had a run time similar to VHS, so I wondered if it might be the sort of best choice all around.
But I learned in the course of our discussion that at least for the professional, Betacam(and later SP) was still the better choice despite the lower resolution. So it sounds like even if we had dropped W-VHS in 1982, professionals would have still preferred Betacam.

At which point I did pivot to a completely different idea about VHS on Zip disks. Apologies.
These hypothetical questions are kind of what I do for fun. My idea of fun is different than most people. Lol! So I run these scenarios in my head about how things might have been different if X technology had been dropped in year Y.
But the truth is, it's more fun for me to base it in reality with technology that actually exists or could potentially/possibly exist, versus completely magical technology. Time machines aside Lol!

So after reaching the conclusion about W-VHS vs Betacam, I pivoted to VHS on Zip disks as a separate topic. Again, apologies. With your wealth of historical and technical knowledge on video tech I was hoping to pick your brain on whether or not you thought such a thing as a VHS signal on a 750MB Zip disk was even possible. And if so, how much of that signal could we fit?

Which is why we were running through how much digital data storage a VHS could hold in 1977 compared to a 750MB Zip disk. My thinking being that if the data density was similar for digital, maybe it would also be for analog. Although I realize I could be completely off base there. I don't understand analog technology anywhere close to as well as I do digital. Although it fascinates me to no end and learning as much about it as I can is great.

Again I appreciate your answers/knowledge tremendously and apologize for switching subjects on you here.

[Cornucopia]

I see. No worries.

In the late 90s/early 2000s, you could put mpeg1 or mpeg2 on a Zip disc. For storage. While the 1.4 Mb/sec read time is what was quoted, that is theoretical and peak, not sustainable. Thus the device would be hard pressed to try to use for continuous playback. I know, I tried.

Plus, the 750 MB size version only came out at the very end of the product life, and at that point it was clear the product wasn't viable long-term. And 100, 200MB isn't enough for whole feature length clips, only small commercial -size segments.

The biggest reason to not use was the "click of death", a corruption of the head seeking mechanics. Once that happened it could spread non-playability to other discs, like a virus. Think of it like a bad wrinkle on a vhs tape that is so bad it damages the rotating playback heads, which in turn cause wrinkles on subsequent tapes. It was a very real problem that our production company personally experienced. In fact it got so bad we made a concerted effort to go through our inventory of discs and drives and transfer off all that we could using the remaining good ones, onto CD-R or hard drive. And then threw all of them in the trash.

Slightly better were the Jaz (one Z) discs & drives. Their mechanics were a bit sturdier, though based on same tech, so they lasted longer. But if the click started on them, you were F'd as well. They did have 1GB and 2GB versions and they were literally much more like harddrives (the zips were literally just glorified floppies) and had high enough sustained access. Our company's use of them lasted a few years beyond use of the Zips. Ultimately they were doomed for long-term use as well, and were abandoned.

A lot of orphaned tech was abandoned for similar usability reasons. If the Jaz had never suffered from CoD at all, it would probably still have lasted well into the 2010s, when SD cards and SSDs made rotating platter harddrives less attractive, performance-wise.


Scott

[roxics]

The biggest reason to not use was the "click of death", a corruption of the head seeking mechanics. Once that happened it could spread non-playability to other discs, like a virus. Think of it like a bad wrinkle on a vhs tape that is so bad it damages the rotating playback heads, which in turn cause wrinkles on subsequent tapes. It was a very real problem that our production company personally experienced. In fact it got so bad we made a concerted effort to go through our inventory of discs and drives and transfer off all that we could using the remaining good ones, onto CD-R or hard drive. And then threw all of them in the trash.

Oh wow, I didn't know that. It's no wonder I haven't really seen them around over the last 20+ years. I just thought it was due to their low memory capacity and the prevalence of CD and then DVD burners on the market. But I do remember them being very popular for the while. Although I never used one. I bought my first CD burner in I think 1999 or maybe 98. At the time I wasn't working professionally with computers and didn't know anyone else who had a zip drive, so I didn't have a need for one. But I remember seeing them around everywhere for a while. I also remember the Superdisk drives, which were similar but not as popular.

I kind of wonder where magnetic floppy disk tech would be today if it had continued. Considering where hard drives have gotten over the decades. Guess we'll never really know. There is HiMD disc released in 2004 which is 1GB. Although that is not a floppy disk nor purely magnetic, but magneto-optical and seems to operate a lot like a tape. I never used the HiMD variety but the standard MD have held up for me well over the years. I don't think I have a single bad disc out of all the discs I recorded in 1999, which is the year I also bought and MD recorder. As a video format that could work, considering Sony did release one Video MD camcorder in the late 90s prior to the release of the HiMD, so it didn't use those greater capacity discs. Anyway, just thinking out loud. Thanks again.