Film-Tech Forum ARCHIVE: D-VHS vs Blu-ray DVD....?

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Posted by Duncan Smith (Member # 1556) on 05-06-2003, 03:12 PM:

COming from a country WITHOUT a HDTV broadcast system I am curious as to how manyof you guys have HDTV in your homes and use the D-VHS format too?

What do you think of Blu-ray DVD technology which has just gone on sale in Japan?

What are the specs of the US HDTV system and is it that good?

Over here in the UK our pal system is obviously better than standard NTSC (625 lines vs 525 and no 3/2 pull down) but I guess HDTV wipes the floor with it. Go as technical as you like with your opinions and facts, if I don't understand some of it, I'll look it up!

Thanks,

Posted by David Stambaugh (Member # 1102) on 05-06-2003, 04:43 PM:

<Paging Bobby Henderson>

The HDTV rollout in the US has been VERY slow. The major TV networks can't even agree on which version they're going to use (most chose 1080i, but I think ABC went with 720p because it's better for sports). Early HDTV settop box receivers had "reception issues" that are being addressed in new chipsets about to be released. Broadcasters are dragging their feet because they don't see overwhelming demand for HDTV plus they can cram several SDTV streams into the same space as 1 HDTV channel uses. I'm generalizing a little and anyone else reading this thread should jump in and fill in some of the blanks I'm leaving. But basically HDTV has just been very slow to catch on.

Having said that, HDTV looks AWESOME. Most of what I've seen has been like the HD Discovery Channel (via satellite) and closed feeds in retail stores. Still haven't seen broadcast HDTV because nobody in Eugene is doing it yet! HDTV is more readily available in larger markets though. Oh yeah, there's the cable TV issue too. Did they ever settle on a system for doing HDTV over cable?

Posted by Evans A Criswell (Member # 381) on 05-06-2003, 08:50 PM:

quote:
Over here in the UK our pal system is obviously better than standard NTSC (625 lines vs 525 and no 3/2 pull down)

625 lines is better than 525, but with PAL, you have to convert 24 fps to 50 fields per second. I hear this is typically done by running the film 4 percent fast, requiring some sort of processing on the audio so it doesn't sound too high pitched. This sounds like a horrible thing to have to do. At least with NTSC, the 2:3 pulldown can be detected enabling the conversion to 480p without combing artifacts (although it's still a 2:3 pattern of frames) and without having to change the speed of the film (except the 1000/1001 slowdown factor due to the change to color TV in 1954, resulting in a 59.94 field per second rate).

As for HDTV, I wish the cable companies would be more speedy about offering it. As for going with 720p because it's better for sports, ABC doesn't realize that very few HDTVs actually display 720p natively, but convert it to something else (1080i, 540p, or 480p), defeating any advantage of using it over 1080i.

I've been HDTV ready for 362 days now, and have watched nothing but cable TV and DVDs!

Posted by Bobby Henderson (Member # 840) on 05-06-2003, 09:28 PM:

The HD-DVD issue is pretty murky. You have the Blu-Ray camp and then Time/Warner and Toshiba want their own format. Basically we're going through the same format war garbage that stalled DVD itself for years.

Meanwhile prices are dropping for D-VHS players. D-VHS "D-Theater" movies may be on magnetic tape, but the picture quality is awesome nonetheless. You're getting 1080 HD video of much better image quality than DVD. The picture quality is even noticeably better than most compressed HD broadcasts. I forget the actual spec on data bandwidth but seem to remember the rate being around 25 to 30 million bits per second. The Dolby Digital data rate is also upped to 576kb/s (higher than the 448kb/s and 384kb/s rates standard for DD 5.1 on DVD).

On the downside, D-VHS movies have very little in terms of extras. However, for most folks the movie is the only thing that matters. My parents fit into that camp and have gone to buying D-VHS movies over DVD whenever possible. And here's a warning: don't leave the tapes anywhere near speakers or the slightest magnetic fields at all. They can erase very easily.

The HD-DVD camp is also pissing me off with talk of puny, low rates of bandwidth. I've heard rumblings that the Toshiba/Time Warner model of HD-DVD would have a bandwidth ceiling of only 15 million bits per second --just a mere 5 megabits above the current standard. They expect to go from 480p to 720p and 1080i with ONLY 5Mb/s extra? Are they on dope!!??

I do like disc-based media for instant data/chapter access, no rewinding, etc. But if the tech-folks cannot up that bandwidth rate at least into the 20Mb/s-25Mb/s ballpark, they might as well not even bother introducing the damned thing. D-VHS is already presenting a higher quality alternative. If they want to come off with a "we don't need to match or surpass D-VHS" attitude and just fob off something "good enough to get by" then they need to kiss my ass. I won't buy it.

On HD-DVD, the disc makers need to do the job right or not don't do it at all.

Posted by David Stambaugh (Member # 1102) on 05-06-2003, 09:34 PM:

Joe Kane has written many articles in which he is very outspoken in his criticism of the HDTV rollout. He also swears that 720p is a better system than 1080i. We got 1080i because it's "easier" to implement and still looks pretty good. It's true that most HD-capable sets cannot do 720p natively though.

Posted by Duncan Smith (Member # 1556) on 05-08-2003, 12:37 PM:

HI Evans, interesting opinion you have there. Your right about the speeding up of 24 fps film to 25fps for transfer but as the audio is sometimes pitch bent back to original and without a direct A-B comparison it barely notices. IMHO the advantages in image quality outway the rest. However I am watching it on a european set running on 240vac 50Hz so I guess the NTSC playback prolly doesn't look as good aon my set as it does on yours, eh?

Another question, if the HDTV signal is 1080 lines surely the set top box could be designed to output a 1080p signal instead of 1080i irrespective of broadcast parameters?

Thanks for the replies, Duncan.

Posted by Brad Miller (Member # 2) on 05-08-2003, 01:45 PM:

D-VHS is wonderful. The image quality on that format must be seen to be believed.

I'm also getting a little tired of the constant hassle of dealing with authoring DVDs and various compression and such. Then if they get a tiny mark on the disc, the thing won't play. At least with D-VHS if something happens to a spot on the tape, it will only affect a couple of seconds of the program. I've never really had a problem with tape. Direct access of discs is great, but for right now D-VHS is the way to go in my opinion.

Posted by Bobby Henderson (Member # 840) on 05-08-2003, 06:24 PM:

Here's a nice little bit of trivia about D-VHS HD movies. Currently, there's little if any copy protection on the tapes at all. The amount of bandwidth and data stored on each tape is staggering, far too much to upload to be practical at all.

And maybe that's the direction Hollywood should take in this copy protection garbage. Just hit us with extreme high rez video far too big for us to use in our computers at all.

Posted by Dave Macaulay (Member # 813) on 05-08-2003, 09:39 PM:

PAL drives me crazy. The image is slightly better I suppose - not enough to really matter IMO, but that damn flicker is horribly annoying. I've been on European jobs for weeks and never got used to it. I can't understand how they tolerate it.

Posted by Leo Enticknap (Member # 534) on 05-12-2003, 02:04 AM:

I can't see that D-VHS has much of a long-term future. DVD is in the process of sidelining analogue VHS for distribution of pre-recorded material, and therefore the expensive process of manufacturing and assembling all the mechanical components of a VHS cassette is going to become less economic as the number of shells being made decreases as a result of falling demand. Even if the encoding method is different with D-VHS, the tape transport mechanism and helical scan head assembly is still largely the same, and is becoming more expensive to manufacture than the laser pickup on a DVD drive.

I agree with Brad - recordable DVDs currently have several major drawbacks, not least fragility. But anyone who was using recordable CDs in the early to mid '90s would have had the same problems. A combination of better media manufacturing techniques and CD drives which are better suited to reading the dye surface has pretty much solved them. The number of audio cassettes being manufactured, meanwhile, continues to decrease every year, and blank CDs are now a lot cheaper than decent quality (e.g. Cr02, with a reasonable quality cassette shell) cassettes.

quote:
And maybe that's the direction Hollywood should take in this copy protection garbage. Just hit us with extreme high rez video far too big for us to use in our computers at all.

It's too big at the moment, but the amount of data on a DVD (and the amount of processing power needed to do the digital to analogue conversion) is way too big for a PC made 10 years ago. Before too long we'll have PCs which can deal with this volume of data, and the absence of an effective copy protection system may well lead the studios to abandon D-VHS as a release format before it becomes obsolete in its own right.

Posted by Mark Gulbrandsen (Member # 72) on 05-12-2003, 08:46 AM:

"He also swears that 720p is a better system than 1080i."
________________________________________________________________
Personally I think Joe Kane needs Lasik surgery! There is far more artifacts present in the 720p broadcasts that Is ee then in the 1080i stuff. Even films I watch broadcast on ABC's 720p system look wierd. The grain is certainly visible but it appears to look somewhat strange, and partly as just an artifact in and of itself. On the other hand 1080i also has artifacts but not so noticable except on certain things such as grass or really fast changiong fine detail. Both systems suffer from pixelization doring dissolves, or fade in/out transition.

Joe Kane needs to be more patient. When B&W brodcast TV was only as old as HDTV it too had its own set of problems. Back then there was no AFC for the tuners and they drifted all over the place requiring touching up the fine tuning every 10 min or so till the set got to operating temperature. Screens were also only 10" in diameter, and most sets contained upwards of 35 vacuum tubes. Reception was also more difficult as TV antennas were also in their infancy. Jow woulda tore his hair out back then.

IMHO, neither system is really good yet....or near its peak operating capability as this is still a new system that is very young. Both the broadcast end and reception end will improve in time.....again

When it comes to deciding on what system a station goes with it boils down to the old industry tradition of who gives who the most for the least. Its always been this way in broadcast.

I have seen a small drop in the prices of HD sets lately though. COSTCO has a direct view 16X9 Samsung set now for 869.00!!

Mark

Posted by Duncan Smith (Member # 1556) on 05-12-2003, 12:57 PM:

Hi Dave, you're right about the flicker! I have never liked it (along with that damn loud HF whistle that the older sets were bad for) but I use a 100Hz flicker TV which really helps. I know it can muddy up movement a bit and resolution but with mine set on a basic level of processing the image is sharper than my old 50 Hz set and the motion rendering is still very acceptable. Are there any 120Hz TV's in the US or do they not exist? It seems the only other option to reduce flicker is some sort of prog scan device like a PDP or LCD projector/tv...?

One good thing about good old blighty is the BBC though. I know they're already using a HDTV system in some areas as I've seen it projected via DLP in tests and it looked very good on a (roughly) 20 foot wide 16 x 9 screen. It had a special BBC HDTV logo on it denoting the format on display. The BBC are pretty good for implementing new technologies in a tried and tested manner. NICAM is a very good system of broadcasting stereo audio over an analogue system and was developed by the BBC if I'm not mistaken.

What is the system for stereo broadcasting on analogue tv in the US, I think it's a FM system in Japan isn't it?

Duncan.

Posted by John Pytlak (Member # 331) on 05-12-2003, 02:59 PM:

quote:
I know they're already using a HDTV system in some areas as I've seen it projected via DLP in tests and it looked very good on a (roughly) 20 foot wide 16 x 9 screen. It had a special BBC HDTV logo on it denoting the format on display.

The International Telecommunications Union (ITU) is trying to take a role in developing digital cinema standards:

http://www.itu.int/itunews/issue/2002/01/interview.html

Here is what a report by David Dawson of the Motion Picture Association (MPA) has to say:

http://www.dawsonteam.com/digital%20cinema/DigitalCinemaReport_2002.doc

quote:
Other international standards bodies such as the Digital Video Broadcasting project (DVB), the International Telecommunications Union (ITU), and the Information Technology for European Advancement (ITEA) have begun similar investigations. While acknowledging the importance of these other standards bodies, the MPA is working closely with the North American Theatre Owners (NATO) association in digital cinema standardization, and encourages these organizations to harmonize their efforts with existing SMPTE and MPEG work already underway, so as to avoid inconsistent standards.

Posted by Steve Kraus (Member # 476) on 05-12-2003, 06:38 PM:

Why would a 50Hz flicker bother you more than the 48Hz flicker of a cinema?

Posted by John Pytlak (Member # 331) on 05-12-2003, 08:39 PM:

quote:
Why would a 50Hz flicker bother you more than the 48Hz flicker of a cinema?

Most television displays are set to a much higher screen luminance than the 16 footlamberts specified for film projection, so flicker is more perceptable.

Posted by Duncan Smith (Member # 1556) on 05-13-2003, 12:51 PM:

Hi Steve,

I think John's right (as always [Smile]

), if the xenon is too bright when lining up the light on screen when for example I change the lamp, it does have a more perceptable flicker (I'm not telling you this like you don't know, merely stating that I have observed it myself).

Interestingly, the last cinema I work at used to do a lot of silent film at speeds as low as 14fps. They have Vic 8's there and 3 bladed shutters to increase the flicker rate. The silent films looked a lot better for it but the standard 24fps and sometimes 25fps looked a lot smoother. If I could get hold of a 3 bladed shutter for my projectors I would, it's worth it despite the light loss. I only run my 1600watt xenons on a low amperage as it is. [thumbsup]

See ya, Duncan.

Posted by Leo Enticknap (Member # 534) on 05-14-2003, 02:51 AM:

Out of interest, what were you running at 14? I know that some purists believe that Griffith films should be run very slowly in places, because Billy Bitzer was a notorious undercranker - Kevin Brownlow's video restoration of The Birth of a Nation has some shots running as slowly as 11fps. But apart from that I don't know of anything that was intended to be run slower than 16. Shooting and projection speeds gradually increased in the years following WWI, because the opening of ever larger cinemas meant that projector designers had to maximise light output. The way they did this was by moving from three blade to two blade shutters, hence the need for higher speeds to avoid visible flickering.

Germany stuck doggedly to 16 pretty much until the conversion to sound. Metropolis, for example, was shot almost entirely at 16 (in 1926) even though British and French studios were generally shooting at 18-20 by then and Hollywood had virtually gone to 24.

So I'd be interested to know where your 14fps films come from.

Posted by Duncan Smith (Member # 1556) on 05-15-2003, 03:58 PM:

Hi Leo,

I don't remember the titles or the specific speeds we ran them at. It was generally regarded that we should run them at a speed that rendered "natural" motion which is subjective to a degree. Of course you've also got the historical factor that even decades ago they were still run at a speed greater than that photographed at in cinemas. This always seemed to provoked debate and in the political arena around at the time some of the decision making was removed from the projectionist. The vast majority of prints came from the BFI film archive and various institutions who's names I was not always privvy to.

Some features I seem to recall needed to be monitored throughout as the speed would change slightly during exhibition (usually by a representative of the distributor who couldn't take his finger off the variable speed control [thumbsdown]

or trust the projectionist).

The best thing about these shows was the pianist playing live by the screen, a little "theatre" added to the proceedings!

Sorry I can't be of any more help, info-wise.

Duncan.