DIY Home Telecine: HD or SD??

[christoph]

there's no such distinction, you must have misunderstood. hd is a concept, hdv is a tape format.

Interesting way to put it but, still, I don't know anyone that thinks HD and HDV conotate the same expected quality.

matt's way to put it is absolutely right here..

the analogy here would be: "i shoot a feature on film" is only technically meaningful if you provide additional info, like, what camera do you use, what lens, which film format, which post chain etc..

similar, saying this is a film in HD doesnt mean it's in theatrical quality, just means that it's in either 720p, 1080i or 1080p.. the camera that it was shot with, the recording medium used, aand the way it was handled in post will all affect how it looks.

to use matt's example: a cinealta recorded to HDV will look better than a Z1U recorded to a uncompressed 10bit 4:4:4 1080i file (unless you're doing greenscreen i guess)

You include HDV along with DVCpro and HDcam and say they all have the same resolution but you previously said that the resolution was dependent on the camera being used.

the pixel count of the frame itself is codec dependend, the recorded resolution from the scene is depended on lens, ccd, signal processing, and storage medium.

++ christoph ++

[edit: fixed quoting and just say that david explained it very nicely on the last page]

[Patrick]

So explain to me how a HD signal can be recorded on MiniDv tape (which is essentially an SD format normally limited to a horizontal resolution of not much more than 500 lines.) I'm puzzled by all these JVC MiniDv camcorders which supposedly record in High Definition.

[mattias]

I don't know anyone that thinks HD and HDV conotate the same expected quality.

it's because when they hear hd they think of the cinealta and when they hear hdv they think of the z1. fair enough, but it's not the truth. there are already higher end cameras that record in the hdv format as well as prosumer ones that record in higher end formats like dvcpro. so in layman's terms even if what you're saying happens to be true now it won't in just a very short while. and for us who are way more educated than most in the field it hasn't been for a long time. and why hdv as a format for telecine should have anything to do with whatever ccd the z1 is using is beyond me.

conceptually, HD is generally seen as theatrical quality resolution while HDV is generally seen as lower than that; broadcast grade, so to speak.

again that's referring to cameras, not the format.

You don't see it that way?

obviously not.

/matt

[mattias]

So explain to me how a HD signal can be recorded on MiniDv tape (which is essentially an SD format normally limited to a horizontal resolution of not much more than 500 lines.)

that's easy. minidv tapes don't record video, they record digital data, just like a hard drive. it's no more strange that you can put whatever data you like on a minidv tape than it is that you can store any resolution images on your computer. you can record text documents and video games on mini dv tapes as well if you like.

then there's the compression issue of course. since hdv fits as many minutes on a tape as dv while it's four times the pixel size it has to be compressed 4 times as much. mpeg-2 is a codec that's at least 4 times more efficient than dv compression, so there you go.

this efficiency is due to the interframe encoding, which is what can cause motion artifacts and lead to trouble in editing. things to take seriously for sure, but to be honest i haven't seen much of either, and i've shot one short film, one music video and one feature on hdv using the z1.

/matt

[christoph]

So explain to me how a HD signal can be recorded on MiniDv tape (which is essentially an SD format normally limited to a horizontal resolution of not much more than 500 lines.) I'm puzzled by all these JVC MiniDv camcorders which supposedly record in High Definition.

because a miniDV is basically just another form of harddisk (there is software that allows you to use a dv cam as backup solution.. though i dont recommend it)

the tape was designed to substain 25mbit video (and some audio).. now with more efficient compression schemes you can put a higher resolution video on it, simple as that. but you're kinda correct, HDV really has no right to look as good as it does.

++ christoph ++

[edit: aargh forget it, there's always somebody faster than me that puts it better ;]

[johnnhud]

Can anyone tell me why you would need a "Mini HD" tape to shoot HDV on? It seems so silly (See above comments) because the tape is just a data storage device. Still I see these tapes at the local electronics store going for about 2 to 3 times what the miniDV tapes go for.



is it just that people are stupid and will buy it because it says HDV? or is there really something to it?

[Patrick]

Maybe it's a similar scenario to the Hi8 and Digital 8 tapes which can both be used in a Digital 8 camera. Although the Digital 8 tapes are more expensive than Hi8 tapes, from what I hear, the image quality is identical.

[filmamigo]

So explain to me how a HD signal can be recorded on MiniDv tape (which is essentially an SD format normally limited to a horizontal resolution of not much more than 500 lines.) I'm puzzled by all these JVC MiniDv camcorders which supposedly record in High Definition.

Because a MiniDV tape is just a plastic shell filled with tape on spools. You could invent a way to record anything you want on MiniDV tape.

It's not dissimilar to other re-uses of tape. You can record video onto Philips audio cassettes (the PixelVision system). You can record a MiniDV-compatible video onto Hi-8 tapes (Sony's Digital 8.) You can record broadcast-quality video onto VHS cassettes (Panasonic's M & MII formats). You can record broadcast quality video onto BetaMax cassettes -- Sony BetaCam, BetaCam-SP (with slight modifications.) Even DigiBeta didn't re-invent the basic tape transport system of BetaMax.

The flexibility is even greater once you start laying down digital data onto tape. You no longer have the limitations of trying to fit enough analog bandwidth onto a particular track length and pitch.

Re: johnnhud

The videotape manufacturers will tell you that the "HD" branded MiniDV tapes are better quality than regular MiniDV. There may be a small improvement (I haven't researched the formulations) but you won't see it in your pictures. The difference between formulations like Oxide and Metal Evaporated were easier to see in analog video. Now, any difference in formulation won't affect picture quality - because the digital signal can either be read or not read. The best you could hope is that the better formulations might be sturdier (less dropouts to corrupt the data).

This is such an old marketing trick -- the manufacturers like to re-use their tooling to deliver "new and improved" formats on the old designs. But they would love to sell "new and higher-priced" tape to the consumers. Sometimes they go so far as to notch tapes or cripple decks to not accept the cheaper tape stock. When I used to shoot/cut S-VHS, I would buy high-grade VHS tape stock and drill out my own notch so that the equipment would accept it as S-VHS. (I was actually buying VHS stock that was better than most S-VHS stock at the time.)

[MovieStuff]

saying this is a film in HD doesnt mean it's in theatrical quality, just means that it's in either 720p, 1080i or 1080p.. the camera that it was shot with, the recording medium used, aand the way it was handled in post will all affect how it looks.

to use matt's example: a cinealta recorded to HDV will look better than a Z1U recorded to a uncompressed 10bit 4:4:4 1080i file (unless you're doing greenscreen i guess)

Okay, I got it now. However, much of this seems to be splitting hairs, in terms of what the terms "HD" and "HDV" mean to people when trying to talk about hi-def video. When someone says, "This is HDV we're talking about, not HD", I don't think there is anything confusing about that statement at all, since it depends on the perception (though a technical mis-perception, perhaps) that HD denotes a higher quality than HDV. Certainly, if someone were talking about making a theatrical feature on "film", your first thought would not be that they were shooting 8mm or even 16mm. There would be a natural assumption they were shooting 35mm. Conversely, someone promoting telecine transfers to "HD" would be remiss if they did not reveal they could only really transfer to HDV within the operating resolution provided by something generally associated with HDV, such as a Sony HVRZ1U or FX1, etc. Thus there is an unconscious link between resolution and the terms HD and HDV, regardless of any technical common ground.

Regarding such, Mattias wrote:

it's because when they hear hd they think of the cinealta and when they hear hdv they think of the z1. fair enough, but it's not the truth.

It's the truth as they understand it based on a distinction promoted by the industry to differentiate between expected results. As Christoph pointed out, HDV was developed as a personal form of HD but has never really be promoted as being as good as HD. This distinction isn't something the consumers came up with but, rather, the industry itself.

there are already higher end cameras that record in the hdv format as well as prosumer ones that record in higher end formats like dvcpro. so in layman's terms even if what you're saying happens to be true now it won't in just a very short while.

But is it true now? I guess that's really the issue (if there is one). I mean, I can remember when Sony was trying to take advantage of confusion over the terms "Beta". There was Betamax and there was also Betacam, both of which used the exact same tape stock and shell. Endless ads promoted Betamax as simply "Beta" because that is how professionals shooting Betacam referred to their format and Sony exploited this misperception to the max. I just find it interesting the this same industry doesn't try to pass HDV off as HD, especially if they share far more common ground technically than Betamax and Betacam ever did!

But thanks for the info, Mattias, Christoph, David and everyone else. This is certainly a lot for an old analog fart like me to digest.

Roger

[Mitch Perkins]

I have refined the Telecine method of KimmoH ( Forum member's Thread :viewtopic.php?t=3709&highlight=) and have made transfers strictly for viewing on TV with DVDs in SD. The quality of the transfers is very good indeed using my GS400 3 chip camcorder. Now here's my question: With the advent of consumer HD camcorders and the general trend today to HD TVs, how much better would such transfers be using a HD camcorder ?We are talking about watching old family Super 8 movies transferred ultimately for TV viewing. Is the resolution that much better and would there be a noticeably better picture to enjoy? There appears to be a good reason to go to HD DVDs because of the archival quality and said longevity of these discs but that is another issue. I am sorry if this topic has been discussed before but my search yielded no direct answers.

- I think the consumer needs to have the "HD" screen to see much/any difference.
- Some will buy into the new thing right away, others not. Follow the numbers [modifying claims made depending on the source], and decide which is the larger market share.
- Neither "HD", nor any other digital formats are currently considered archival. The film itself is the archive.
- Meanwhile the SD looks absolutely just great [as long as the film itself does], and since the film will have been freshly cleaned and assembled/edited into a new presentation, the viewing experience will be pleasurable.

My two cents.

Mitch

[christoph]

roger,

i think the confusion is that is you state "HDV is not as good as HD" that you dont specify clearly what flavor of HD you are comparing it to. if you'd say "HDV is a lower quality codec than HDCAM" nobody would disagree... but the term "HD" itself just doesnt say zilich. your HD broadcast signal will be higher compressed than HDV, as will the HD-DVDs and Blue-Ray discs, and this is how most people will get in contact with HD.

for reference, the best industry HD signal is uncompressed 4:4:4 10bit 1080p, which requires dual HD-SDI because the dataflow is terribly high. the most often used one in high-end work is 4:2:2 10bit 1080p, either uncompressed to disk or slightly compressed to HDCAM SR. the first you can conveniently record is HDCAM 3:1:1 8bit 1080i/p (which is not full raster, but 1440x1080 pixels). the only ones affordable to mortal men are DVCPRO HD, XDCAM HD, HDV et all, all of which are heavily compressed but still can look very good (provided the source material is any good). their limitations become only really visible if you do heavy post-manipulation.

i though the comparison to Digibeta, DV, DVCPRO 50, Beta SP all being SD signals (with their strenghts and weaknesses) was pretty good. better have a spirit transfer to DV than a DIY transfer to uncompressed 4:2:2 10bit imo.

hope that doesnt add up more to the confusion
++ christoph ++

[MovieStuff]

roger,

i think the confusion is that is you state "HDV is not as good as HD" that you dont specify clearly what flavor of HD you are comparing it to.

Because no else commonly does, either. That's the whole point. I totally understand that HD is the concept of having a higher definition video image than standard definition video and that HDV is only one format within the category called "HD". I get it now. But, supporting that explanation by pointing out that HDV could technically carry the maximum resolution of a 1080P camera if a 1080P camera were fed into an HDV deck begs the question "does anyone really do that?" Do people in the motion picture industry really refer to something produced at 1080P as "HDV". From what I've seen, producers will be very quick to point out they shot in "true HD" and not just "HDV".

This isn't about what I understand or even about your definitions of the terms, no matter how accurate. This is about the distinction that is promoted within the industry between HD and HDV. "HD" is very much promoted as something unique and above "HDV" even though HDV technically falls within the category called HD. Again, definitions be damned, the common perception is that HD represents a better, higher resolution image than HDV. Producers working in what they consider to be "true HD" theatrically will never accept that idea that they were merely working in "Hi Definition Video", even if that is the truth. In short, people working in HDV may accurately promote their work as HD but people working with a Cinealta are not going to entertain the idea they are working in HDV or that HDV is going to provide the same results. They are going to hold on to the notion that HDV means a lower quality image than "true HD". So there is a perception difference, for better or for worse, because it delineates how people talk about the medium.

Roger

[filmamigo]

The other interesting twist in the "is it HDV or not" question is that some HDV cameras offer HD-SDI outputs. These outputs by-pass the torturous MPEG-2 HDV compression.

As a result, there are people using HDV-based cameras to record to HDCAM decks or (more likely) directly to hard drive on a computer via BlackMagic HD-SDI connection. This is definitely not HDV... it's like HDCAM shot with lesser lenses...

The big drawback is having your camera tethered to a huge, expensive recording system. I think I'd rather pony up for a cheap ARRI 35BL rental and have something more portable.

[MovieStuff]

The other interesting twist in the "is it HDV or not" question is that some HDV cameras offer HD-SDI outputs. These outputs by-pass the torturous MPEG-2 HDV compression.

As a result, there are people using HDV-based cameras to record to HDCAM decks or (more likely) directly to hard drive on a computer via BlackMagic HD-SDI connection. This is definitely not HDV... it's like HDCAM shot with lesser lenses...

You bring up a good point.

While one could plug the output of a broadcast camera into a VHS deck and record a standard composite signal, it certainly isn't going to look as good as recording the same composite video on 1 inch type C. Still, if the analogy that HD and HDV are really the same thing, then so would 1 inch and VHS. But they were never consider remotely the same, even though they shared a common technology. If someone said they were working in a TV studio and made a recording of a live performance, it is doubtful anyone would assume VHS was being used, though obviously nothing would prevent them from doing so.

Likewise, if someone in the early 80s said they just came home with a brand new Beta camcorder, it is highly unlikely that anyone would assume they just spent $50,000 on an Ikegami Betacam unit. Similarly, if someone working in broadcast said they just made an acquisition of 6 Beta units for their news department, it is equally unlikely anyone would assume they were shooting the evening news on Betamax camcorders.

Even though both the standard Betacams and Betamax camcorders used the very same tape with different labels, people inherently understood the difference between studio "Beta" and home "Beta", even if Sony tried to confuse the issue with marketing. In the same sense, when someone in Hollywood says they are working in "HD", it is unlikely they are referring to a typical "HDV" Sony FX1. Additional clarification isn't really needed unless they were shooting a feature with such a low end camera/format.

Thus, context is everything, in terms of how people perceive the terms "HD" and "HDV". If working in a professional environment such as the motion picture industry, they are not going to assume an "HD" production is using an HDV camcorder any more than they would assume that 16mm is being used for a theatrical film production instead of 35mm. And if someone says they offer to shoot weddings in HD, I don't think anyone expects them to show up with a Cinealta nor would an explanation be required if they didn't.

I agree with Mattias and Christoph and David that "HD" is a 'concept' and reflects resolution higher than standard definition and that "HDV" is a specific format within that concept. I can accept that. However I also think that, in the minds of the industry and general public, "HDV" is a competing 'concept' that inherently reflects lower expectations than theatrical or even broadcast HD, even if it flies in the face of all technical explanations to the contrary. Based on my day to day dealings with other professionals and consumers, people just assume that "HDV" isn't as good as "HD" and I'm not sure how that perception will ever change, since big budget producers with Cinealtas will never accept nor promote the notion that HDV and HD are the same thing. In the end, no matter how much technology changes, common interpretation may win out over technical accuracy here.

Roger

[mathis]

- Meanwhile the SD looks absolutely just great [as long as the film itself does], and since the film will have been freshly cleaned and assembled/edited into a new presentation, the viewing experience will be pleasurable.

On the TV set SD can be just great. The problem starts on Displays, be it computer monitors or Plasmas or whatever.