HDV on the Big Screen

[Leo Anthony Vale]

All this said - in my daily work, which is SD for television, HDV has replaced DigiBeta and DVCPro 50 as the shooting format of choice. Not because it's cheaper (that's a non-issue with commercials etc. - i'm not the one paying the bills), but rather because it simply looks better.

 

---Or is it that it's this weeks hot new trend.

Commercial clients can be quite trend addicted.

 

---LV

[Stephen Williams]

(correct me if i'm wrong, but isn't film negative somewhere around 9-10 stops at best?).

 

 

Hi,

 

Modern film has a dynamic range over 12 stops.

 

Latitude is the amount you can underexpose or overexpose and still get a good resut. I don't see how the latitude of the Dalsa could be more than -2 to +1 (3 stops).

 

Stephen

[Phil Rhodes]

Hi,

 

35mm isn't 4k. I've looked at scans at 2 and 4 side by side and all you're doing is resolving more grain.

 

Now, if you are coming off 35 and going back to 35 with the digital step as an intermediate, then you obviously do need to be clearly resolving grain off the camera neg before you can call it a transparent process. But that doesn't magically mean 35mm resolves 4000 lines. The degradation of going between dissimilar media makes higher demands on the process than staying in one medium would.

 

I think a decent uncompressed, unsubsampled 2K digital capture followed by 2K digital projection would meet or exceed the perceived sharpness of the average current show print. Making DI completely transparent is not a test bed for what we should be looking for in end-to-end digital production.

 

That said, of course 4k to 4k would be outstanding, considerably outresolving current 35mm show prints.

 

Phil

[Max Jacoby]

35mm isn't 4k. I've looked at scans at 2 and 4 side by side and all you're doing is resolving more grain.

 

Oh Phil please, just because you have a chronic aversion to grain... Then please explain why a 4K looks sharper with less aliasing than a 2K scan.

[David Mullen ASC]

Two other points I want to make:

 

First, there are valid arguments for using technologies, processes, formats, etc. that are below the best you can achieve with 35mm. Arguments may be financial (i.e. I have no choice but to explore other options) or artistic (this project needs the look of 500 ASA stock pushed two stops or this face looks better shot with an old Cooke Panchro lens) or logistic (I'm shooting the whole movie handheld and lighter lenses means more to me than sharper lenses).

 

So I've been mainly talking purely technically in regards to HD versus 35mm, not artistically.

 

Second, decisions that cost you in technical quality are accumulative, hence why a DP has to be realistic, if not even hyper-picky, about these subtleties. On its own, maybe this much compression or that much subsampling or that quality of zoom lenses or that filter or film stock or printing from an IN instead of O-neg may not produce a significant hit in image quality, but combined, it can start to add up. Hence why when I want the halation effects of ProMist diffusion, for example, I try and find sharper lenses to use it with, or use sharper lighting with enough contrast to retain some feeling of sharpness despite the diffusion. Because soft lens + soft light + soft film stock + multiple generations for printing + bad projection... well, you get the drift. This is also why I don't slap a lot of heavy diffusion when I shoot HD for theatrical projection (except for an artistic effect).

 

This is also why one has to recognize the weakness of 4:1:1 versus 4:2:2 versus 4:4:4, because on some types of shots, you may not notice the loss of chroma information, but on others you will, especially in a color-correction session and even more especially if you have do to any chroma key work. Same goes for compression artifacts. In an ideal digital world not based on current reality, one would enter into post-production with ALL the information that the digital camera was capable of capturing and save compression and color subsampling for the distribution end, not the origination end. This is also one of the chief arguments for film origination since it allows you so much information to work with in post, at which point, you can get rid of some of it for creative reasons.

[K Borowski]

Thanks Eki! I appreciate the effort you went to with the examples.

 

As to posters detracting video (any video it seems) there are those who have a vested interest in keeping film alive as long as possible because they work in an area where film is essential to their income--i.e., cam sales, film sales, film development/processing (including intermediate work), or even cinematographers who would like to keep people out of the business. Cinematography for the masses is a threatening proposition to older film people. I understand that. What I don't understand is the lack of moral fibre that causes them to react the way they do. They really need to get a backbone and grow-up. I have a test on my website (I have a website for my clients--mostly churches) that I put up some time ago where people could look for themselves at still frames from films shot on both video and film, and try to guess which came from which. No one has ever been able to tell which stills came from film on a consistent basis. Its a cakewalk getting video's gamma/color etc. to look like film. A mini35 adapter will take care of DOF issues (which I think is the single most abused effect in films today). And once you get your motion blur down (i.e.--24P) the only other difference is how much detail you have left after stretching things out on a big screen. From What I saw in "November" I have to think that HDV will look just that much better and good enough so that no one in their right mind would give a darn about wasting tons of money on film and film development if they didn't need to. After all cineplexes go digital it will even things out even more. Motion pictures shot on video look considerably better without the 35mm transfer process and of course--the cost of doing so will become moot.

 

With all due respect, doing a comparison of film and video on a computer is not at all a fair comparison. With regards to people having a vested interest in keeping film alive, you're absolutely right they want it to continue on; why wouldn't they? For more than 100 years, there's been an entire industry that has grown around film processing, developing, timing, and manipulating. Because video has FINALLY gotten to the point where it is passable on the big screen is now an excuse to obsolete a technology that is probably one of the most economically cost-efficient long term? Film continues to improve, and I feel it is cheaper in the long run to use 16mm equipment than bounce between endless computer upgrades and camera "improvements". The new Vision2 50D in 16mm is going to make for some truly impressive blowups to 35, and will make the format even more viable as a professional medium. The fact remains that HDV has the same ammount of visual information as DV; it's just that they've come up with a more efficient means of compressing it. Compression that is not lossless compression will invariably produce very visible artifacts. I have heard of one shoot that used it recently that had to really avoid panning quickly because the pixelation and compression artifacts would become very noticeable if they did a sudden camera movement. I will continue to support film origination because of its high quality and superior color. I hate using the word superior, because it has been misused so often to refer to DV. Film origination has never bene about resolution first either. It has always been used primarily for contrast and color capacity (or dynamic capacity with B&W film). Why else would 35mm be used for standard definition television despite the fact that it is big time overkill, orders of magnitude greater than the resolution that would be needed for SD TV?

[David Mullen ASC]

If a scan can't resolve all the film grain, then it is also throwing out extremely fine detail. This is one reason why more and more scanning for D.I.'s is being done at 4K even if it is downrezzed after that to 2K -- because one CAN see a difference in definition.

 

Now there may be a creative advantage to a 2K scan acting as form of degraining, especially when mixing film stocks of different speeds and trying to make it all look the same. But one should admit that you are throwing away information with a 2K scan of 35mm.

 

I mean, just look at the examples in the Millimeter article I posted -- you are clearly losing more than just grain with a 2K scan. There is also some loss of fine edges.

[K Borowski]

35mm is roughly 4K equivalent, if not 6K -- 65mm would be more like 8K.

 

It's only because Hollywood has compromised by using 2K for most special effects work that people start to think that 35mm is only 2K, when tests clearly show that it is capable of resolving much more -- hence the move to start to do D.I.'s at 4K.

 

Even right now, I'm doing 2K digital effects for a 35mm anamorphic feature that I'm answer-printing, and I can see the resolution hit of doing all the digital work at 2K when I project the results at the lab.

 

Take a look at this article:

 

http://millimeter.com/mag/video_digital_ci...cial/index.html

 

As for the Dalsa, it's 4K but using a single CCD with a Bayer filter, which means that it has to process the RAW signal to derive 4K RGB, so in practical reality, it's more like 2 to 3K in resolution. However, since it is a grainless image, it looks similar to a 4K scan of a fine-grained 35mm stock. And in terms of graininess, yes, it would resemble 65mm. But not in terms of resolution.

 

Now if we could digitally project 4K from a 4K scan of 35mm, or a 4K digital camera, then THAT would seem more like 70mm print projection.

 

In other words, the Dalsa is the first camera to come close to matching 35mm resolution. And it takes a mini-fridge-sized recorder that can only hold two hours of footage at that quality level...

 

As for the argument by Charlie that 35mm is overkill in quality for theatrical features, I'm not sure why he is so desparate to argue for a lowering of standards. We should be working to raise digital cameras to the level of what we currently already have with 35mm, not settling for half the resolution and a quarter of the color information and making THAT the standard for cinema. Why in the world should we do that? We'll only end up regretting it.

 

These sorts of oddly militant arguments tend to be made by people who can't afford to shoot with better technology -- which is fine, there's nothing wrong with working within a tight budget -- but rather than admit any technical shortcomings in their approach, would rather argue either that (2) the technical shortcomings don't actually exist or (2) they don't actually matter. Sometimes they even try to make BOTH arguments, which is somewhat contradictory.

 

Any visual artist worth their salt doesn't use the standards of the common viewer as a guide to the quality level they wish to work at. If they care about their own artform, they set personal standards that are much higher than the average person. The average person won't say they care if a face is well-lit as long as they can see what's happening on screen, but even the average filmmakers care more about such things -- that's the nature of art and entertainment, we put a lot of unnoticed craftsmenship into our work so that the viewer can just enjoy it. We create the ILLUSION that it was all easy. I really don't care if the average person can see the difference between 1K, 2K, 4K, or the difference between 100 ASA and 500 ASA stock, or the difference between 1.85 and 2.35, or the difference between whether a camera is slightly above or below the actor's eyeline, or whether the scene is slightly cool or warm, etc. The point is that WE care so that the audience doesn't have to.

 

So why even go into filmmaking if you don't care about the quality of what you do beyond the level of a non-filmmaker??? WE'RE supposed to be the experts here, not the audience.

 

I really think you're onto something there with most people not noticing. It's almost psychological. People don't notice the subtle camera placement or the photographic irony that can get very heavy in movies the likes of Pulp Fiction, but they FEEL it, even though they can't put their finger on it. People who saw the latest two Star Wars films couldn't tell that it was shot on HD, but they could feel that it was different from other movies. A lot of filmmaking could be described as subliminal messaging. You can't put your finger on it, but it affects the way the movie feels.

 

Regards.

~Karl Borowski

[Guest Charlie Seper]

"I'm sorry Charlie, but these arguments of yours are getting really tedious. If you can't see the difference or don't care, don't expect everyone else to lower their standards to your level. If you are happy with the way HDV looks, fine. But if I were you I'd seriously wonder why most films are still shot on 35mm, despite the added cost."

 

Your lack of honesty is the only tedious thing around here. Now what I'd like to know is why anybody with the common sense God gave a mushroom, after having had it stuck to them for years and years with ridiculously overpriced film and film development prices, which are as close to price gouging as anything ever sold in America or most countries, would be not only looking down on something that could bail you out from the holdup man, but actually have you defending the assailers. Anybody who would purposely go out of their way to defend this nonsense is either too dumb to know better, or more likely, an incredibly immoral person who somewhere down the line is making money from film sales/development, or film cam sales and is not the person they claim to be. Either that or you're suffering from Stockholm Syndrome.

 

"As a "video guy" who has learned a lot about lighting and production from these "film guys," your utter rejection of reality makes me ashamed to be a "video guy." You're giving us a bad name, and I hope people don't hold it against me (us)."

 

Your giving yourself a bad name with your damn stupidity.

 

Now I clearly expect the bad hair lady to go running off with her tail between her legs like she did the first time I posted that video test, since she knew she couldn't pass it, but for the rest of you (I mean the ones that aren't the same idiot with the multitudes of usernames) here's another kind of test for you, which I'm sure you'll find a reason for not being able to pass rather than face the obvious:

 

The two pics are the same, one is the original still photo in its uncompressed 4:2:2, the other was dropped down to 4:1:1 and then bumped back up to 4:2:2. Both are 100% compressed standard jpg's. They're locked in a Flash file. Its around 3meg's.

 

4:1:1-4:2:2 Test

 

The second test is the same pick, one the original 4:2:2 file, the other a 4:1:1 file with 75% standard compression.

 

Compression Test

 

All photos are 1608 x 1200. This really ought to be a piec of cake for those of you who make claims of such superiority of vision. I can hear the excuses starting already....

Edited December 9, 2005 by Charlie Seper

[Chris Keth]

All photos are 1608 x 1200. This really ought to be a piec of cake for those of you who make claims of such superiority of vision. I can hear the excuses starting already....

 

 

Jesus, are you always such a prick? Is it because you're a sound guy trying to argue with a bunch of film and video professionals? Generally, civil arguments are better looked upon than insulting an entire forum full of professionals.

Edited December 9, 2005 by Christopher D. Keth

[Erkki Halkka]

The fact remains that HDV has the same ammount of visual information as DV; it's just that they've come up with a more efficient means of compressing it.

 

No, no, and no. That is simply untrue. HDV has the same amount of DATA, but about four times more resolution, both in luminance and chroma (4.5 in NTSC, 3,75 in PAL).

 

Because HDV uses the (much mocked) long-gop mpg compression, the resulting imagery is MUCH better than it would have been at the same data rate using intra-frame compression.

 

The HDV compression is similar to best quality DVD compression, just with 4 times more resolution and 4 times more data.

 

DVD's use about 1/4 of the data rate compared to MiniDV. The visual quality is roughly on par, because of better compression. If what you said about HDV was true, DVD's should have just 1/4 of the visual information compared to MiniDV.

 

The downside of long-gop compression is, as you mentioned, the possibility of getting bad artifacts when there's a lot of motion in big areas of the frame. I personally have only shot one shot where this became a real problem (a greenscreen shot with fast moving, transparent plastic bag). We managed to fix the shot by applying additional motion blur in the post, but it was a close call...

 

Why else would 35mm be used for standard definition television despite the fact that it is big time overkill, orders of magnitude greater than the resolution that would be needed for SD TV?

 

Partly because it's a habbit, partly because of better color correction abilities in telecine, partly because of bigger resolution.

 

Why is that bigger resolution necessary?? First of all, most video cameras simply don't resolve even the full standard definition resolution in practice. Without electronical / digital sharpening, the images look soft. This happens also in pro formats, like DigiBeta and DVCPro50 etc. Only recently we've started to get cameras that actually produce sharp images without additional sharpening.

 

Second, with bigger original resolution, you have the ability to re-frame / enlarge the pictures in post, without sacrifying quality. This is a big bonus, especially in SFX work.

 

Also, the video shooting formats use 4:2:2 color sampling at best. This becomes an issue when i.e. trying to create perfect bluescreen composites.

 

The reason why i've moved to HDV from "pro" SD video formats is the same. Because every pixel in the final SD master is combined from four original pixels, i get effectively 4:4:4 color sampling. The image is as sharp as one can get at SD, without additional sharpening. I can reframe the shots to some extent without losing visual quality, also because of the 4X oversampling.

 

Believe or not, also color correction works better with HDV than with regular SD footage - again because of the oversampling. Now i can shoot slightly underexposed, to keep the highlights from clipping a bit better, and adjust gamma to brighten the image. This causes the noise levels to pick up, but because each pixel is averaged from four, i can do much bigger adjustments before the noise starts to show in the SD master.

 

The fact that i can digitize and edit everything on my home workstation "as is" is a bonus - i do have an SDI card on the machine, but i don't own a DigiBeta or DVCPro50 deck, so untill HDV i had to rent those if i wanted to digitize at home. Or go to an editing facility to do the work...

 

So, using HDV is definitely not a "trend" issue for me, it's a big positive step both in quality AND in ease of production.

 

****

 

Here's some example images of color spaces in action, if people want to see the differences with their own eyes:

 

http://eki.pp.fi/temp/Eki/ColorSampling/

 

http://eki.pp.fi/temp/Eki/ColorSampling/Co...xamples_444.png

Saved to uncompressed 4:4:4 avi, then exported to .png. This is exatly the same as original text graphic.

 

http://eki.pp.fi/temp/Eki/ColorSampling/Co..._420_HDV_D1.png

This is the graphic upscaled and saved to HDV .m2t stream, then downscaled to SD resolution, then png'd. Even though HDV is 4:2:0, the effective color sampling at SD resolution is about 4:4:4.

 

http://eki.pp.fi/temp/Eki/ColorSampling/Co...22_DVCPRO50.png

This is the same graphic saved as DVCPro50 codec 4:2:2 avi, then png'd. If you look closely, you see a bit of color sampling artifacts here.

 

http://eki.pp.fi/temp/Eki/ColorSampling/Co...s_420_PALDV.png

This is the graphic saved as PAL MiniDV avi, 4:2:0, the red and blue text look rather horrendous. The result is similar to HDV's color sampling at full resolution.

 

http://eki.pp.fi/temp/Eki/ColorSampling/Co..._411_NTSCDV.png

This is the graphic saved as NTSC MiniDV avi, 4:1:1, the red and blue text look rather horrendous again.

Edited December 9, 2005 by Eki Halkka

[Erkki Halkka]

---Or is it that it's this weeks hot new trend.

Commercial clients can be quite trend addicted.

 

Well, the hot trend with clients continues to be film. But as they're paying the bills, many of them (well, most here in Finland nowdays) make do with something that's "close enough" ;-)

 

Actually, one big reason to use film for SD i forgot to mention earlier, is that clients want "the film look". Actually shooting film is a sure way to get it.

 

Also, shooting film has a bit of "glamour" or "magic" attached to it, that has nothing to do with actual imagery. It makes clients feel "this is big time" - and pay the "big time" bills happily...

[Max Jacoby]

Now what I'd like to know is why anybody with the common sense God gave a mushroom, after having had it stuck to them for years and years with ridiculously overpriced film and film development prices, which are as close to price gouging as anything ever sold in America or most countries, ...

Damn right you are! If it wasn't for those outrageous film and development prices, this country wouldn't have such a huge deficit in its budget.

 

I am going to write to my MP this minute! I suggest you do the same.

[Erkki Halkka]

Hi,

 

Modern film has a dynamic range over 12 stops.

 

Latitude is the amount you can underexpose or overexpose and still get a good resut. I don't see how the latitude of the Dalsa could be more than -2 to +1 (3 stops).

 

Stephen

 

Here's what they say at Dalsa site:

 

"Origin's exposure latitude is comparable to the best film stocks and offers at least 12 stops of linear response for an astonishing range in the whites as well as the blacks. In one shot Origin can handle both the naked flame of a candle and the delicate, nuanced shadows on candlelit faces. It can handle the full glare of the sun reflected from a window and still resolve the subtleties of the shadows below. When you light for profound effects, you'll appreciate Origin's profound advantages."

[Max Jacoby]

I'd rather see that with my own eyes than read about it from the manufacturer's website though.

[Jason Debus]

Anybody who would purposely go out of their way to defend this nonsense is either too dumb to know better, or more likely, an incredibly immoral person who somewhere down the line is making money from film sales/development, or film cam sales and is not the person they claim to be.

 

If I'm reading you correctly, you are saying HDV is as good as film and this is simply not true. HD 1080p 4:4:4 isn't technically as good as film, let alone HDV. It doesn't save the loads of cash you are suggesting either, I've heard it's somewhere in the 5% savings range versus film for the TV shows that are using it.

 

Video will not be an equal to film until:

 

1. it meets the same technical specifications (latitude, depth, color, resolution, etc.)

2. it is capable of high frame rates for super slo mo (400+ fps)

3. it is a 'worldwide' format (currently film is the only worldwide format)

4. it's shelf life approches that of film which is 100+ years, which also is future proof.

5. video cameras become as small and durable as film cameras.

6. larger sensors for shallow depth of field

 

Video is getting close to meeting some of this criteria in the more expensive HD cameras, but it is a ways off before it becomes a direct replacement for film that is for sure. I'm not sure why you are insisting that everyone who KNOWS this to be true is dumb.

 

EDIT: And those reasons don't even bring up the fact that the thousands of theaters around the world use film projectors and aren't going to switch to video projectors anytime soon.

Edited December 10, 2005 by Jason Debus

[Erkki Halkka]

I'd rather see that with my own eyes than read about it from the manufacturer's website though.

 

Origin outputs 16 bit HDRI (high dynamic range images), as far as i know. Here's a bit of info about HDRI in general:

 

http://en.wikipedia.org/wiki/HDRI

 

There's two standard dynamic range 16 bit TIFF stills at their site, available for download. These are only 2K resolution, probably scaled down to get the size manageable - the zips are 12Mb each. These have already been "exposed" from the raw HDR originals - so color correcting these gives poorer results than color correcting the originals, AFAIK.

 

http://www.dalsa.com/dc/documents/documents.asp

 

However, i did a bit of gamma adjustment to the images just for fun, both darkening and lightening the pics - because of the image being 16 bit, the result of my rather extreme adjustments weren't that bad... there's some noise in the lightened shadows, not sure if that'd be present if the adjustment was done using the original, raw file.

 

These are 8 bit png's, so they're much smaller downloads...

 

http://eki.pp.fi/temp/Eki/Dalsa/

[Erkki Halkka]

Video will not be an equal to film until:

 

Of course, digital cinema has some clear advantages over film too - like being able to monitor the shoot at full quality in real time, checking "dailies" at full quality on location, possibility to even make a full quality edit of the scene at location, ability to shoot an hour in a row, no telecine needed for digital intermediate, no generation loss whatsoever if projected digitally etc.

 

...it's a different beast. In many ways not as good as film, but in other ways - better.

 

And those reasons don't even bring up the fact that the thousands of theaters around the world use film projectors and aren't going to switch to video projectors anytime soon.

 

Dunno - it's a matter of economics. As soon as the projector prices drop under certain treshold, the change will probably be very fast. Film prints are expensive - moving data around is cheap.

[Scott Fritzshall]

The reason why i've moved to HDV from "pro" SD video formats is the same. Because every pixel in the final SD master is combined from four original pixels, i get effectively 4:4:4 color sampling. The image is as sharp as one can get at SD, without additional sharpening. I can reframe the shots to some extent without losing visual quality, also because of the 4X oversampling.

I've got to ask, are you absolutely certain that this is true? Because from what I've heard, many HDV cameras actually upsample from something like only slightly higher than DV resolution to get to 1440x1080. If this was the case, then you wouldn't really be increasing your color sampling in the end.

[Sam Wells]

People who saw the latest two Star Wars films couldn't tell that it was shot on HD, but they could feel that it was different from other movies. A lot of filmmaking could be described as subliminal messaging. You can't put your finger on it, but it affects the way the movie feels.

 

Regards.

~Karl Borowski

 

I agree with you. I'm not sure I'd call it subliminal (I'm wary of that one !) but I think we're responding to more cues than can simply be explained - or explained away - by resolution figures. In fact resolution per se does not always predict percieved image sharpness.

 

It's also very important to remember we're dealing with motion pictures here; we're not. in the act of watching them studying static images but rapid succesion of still images that we're processing into the appearance of motion.

 

-Sam

[K Borowski]

Eki: The same ammount of space is available on the tape. They aren't making the pixels smaller; therefore it is the same ammount of information, albeit recorded in a more efficient fashion. Of course it looks better than Mini-DV. Heck, HI-8 does ;-) As for me questioning the use of 35mm for television, it was a rhetorical question. I understand that English is probably not your first language; I basically am saying that 35mm is used for reasons other than its extremely high resolution, namely that you have a future-proof file with a much broader color gamut than television can ever provide. My own personal take is that people should shoot everything as if it were to be shown on the big screen, so the material won't be outdated as future imaging technologies evolve. I've seen too many old TV shows look silly in color or silly in even modern standard def. coming over a clear cable signal.

 

I agree with you. I'm not sure I'd call it subliminal (I'm wary of that one !) but I think we're responding to more cues than can simply be explained - or explained away - by resolution figures. In fact resolution per se does not always predict percieved image sharpness.

 

It's also very important to remember we're dealing with motion pictures here; we're not. in the act of watching them studying static images but rapid succesion of still images that we're processing into the appearance of motion.

 

-Sam

 

I wish there were a word that had the same meaning as subliminal without all of the negative connotations. I don't want to come across as if I mean subliminal ala Josie and the Pussycats. What I'm saying is that most people can recognize artistic composition, lighting, framing, etc. without being able to consciously describe it. They know it is there and (usually) appreciate it without being able to verbalize it.

 

Regards.

~Karl Borowski

[Tomas Koolhaas]

I'm VERY aware of these limitations. If you took a look at that pop vid i linked to, you probably noticed that it has both chroma keying and strong color correction. All 200 shots of it.

 

I'm not saying it was a walk in the park to do it... and the result wasn't perfect at HD resolution. This was not a surprise, knowing the limitations. But i'd still say it it was *passable*.

Did i suggest it was easy, or that HDV is *just as good* as film?? I don't think so...

 

The format has limitations, but i think they are a smaller issue than you think - they can be mostly overcome.

 

I was talking about it probably being passable as 35mm in SOME scenes. You know, scenes that do not need that much post and don't have that much DOF. Cut within the film, not in a controlled A / B test.

I'm aware that what you can do with HDV in post colorwise is more limited than what you can do with a good film scan. That's a non-issue.

 

What i'm trying to say, is that if you take these limitations into account, and know what you are doing, you CAN get very good stuff out of it. Maybe not perfect, but passable.

 

To get good stuff outta it, you need to light, shoot and post knowing your medium. People who are used on working in film may not always be the best choice when working on a video format. It's a different beast.

BTW, do you think that in some scenes, HDCAM could be mistaken for film??

 

I haven't worked that much with HDCAM footage lately, but the shots i HAVE done post on, didn't really look much different from HDV. The ones i worked on last time were actually slightly more video-like than my own HDV shots i compared them with, but that was mainly because the DOP had used too much sharpening in the camera.

 

Anyway, HDV is a bit lower in technical quality compared to HDCAM, but not THAT much.

 

Resolution is the same. Bit depth is the same.

 

Color spaces are HDCAM's 17:6:6 (which is roughly 4:1,3:1,3) VS HDV's 4:2:0. HDCAM is only slightly better in this regard, HDCAM saves about 1/3, and HDV 1/4 of the color information.

 

Even though HDV's compressed much more, the compression algorithm is better/more efficient. HDCAM probably has the edge here though - it should be roughly the same difference as between MiniDV and DVD.

 

The HDV results should be visually very close to what you get from HDCAM - the technical difference is much smaller than i.e. between MiniDV and DigiBeta - and much, much smaller than the difference between a good DOP and a bad DOP...

Well, one could always shoot in the fake progressive mode, if afraid of the motion artifacts. It still has double the resolution of MiniDv, possibly more, depending on how it's done in the cam.

 

But, as i mentioned, with good algorithms, one can get really good results when de-interlacing. If you wish, i can post examples or something.

That's why i said "not exactly there, but closer".

 

 

Hi,

Eki, I was wondering whether you thought it is accurate to say that you can achieve the same resolution with cheap "HD" lenses that you have on HDV camera versus top-of-the-range HD lenses that can be utilised on HDCAM camera's such as the F900. I haven't used HDV yet so I don't know, I just think it seems unlikely.

Cheers.

[Erkki Halkka]

I've got to ask, are you absolutely certain that this is true? Because from what I've heard, many HDV cameras actually upsample from something like only slightly higher than DV resolution to get to 1440x1080. If this was the case, then you wouldn't really be increasing your color sampling in the end.

 

Yep, i'm pretty sure. The following is mostly from reading "reliable sources", but i've filled in some blanks myself... correct me if i'm wrong - that's happened before.

 

Ahhem...

 

The color information is kept intact untill compressing to HDV mpeg. Sony's HVR-Z1, the HDV camera i'm most familiar with, has three 960 x 1080 CCD's, which should give something very close to full 1920*1080 luma resolution with pixel shift, theoretically. The green pixels are offsetted by half a pixel from blue and red - the luma signal is calculated from these all.

 

In practice, the optics are probably to blame for the fact that the real life resolution is lower - just as with most standard definition video cameras... but it's still much, much better than SD.

 

The chroma information, AFAIK, is 960*1080 at this stage. You could call it 4:2:2 "in camera".

 

From these, the data is reduced (scaled) to 1440*1080 luma signal / 720*540 chroma signals, then compressed.

 

As PAL resolution is 720*576, the actual color sampling of downscaled HDV seems to be 4:3,75:3,75. In NTSC, one should get full 4:4:4.

 

My real life tests suggest that this holds true - i like examples - wanna see one??

 

 

On the left side, HDV footage downscaled to uncompressed PAL D1 video. All color channels are clean, more or less perfect. Better than with i.e. DigiBeta.

 

On the right side, there's yet another example of MiniDV's color sampling problems you can't tell the difference looking at the full color image, but looking at the individual channels (or trying to do chromakey)... you see it ;-)

[Erkki Halkka]

Eki: The same ammount of space is available on the tape. They aren't making the pixels smaller; therefore it is the same ammount of information, albeit recorded in a more efficient fashion.

 

You are mixing up visual information (how the actual images look) and datarate. They are two different things.

 

Here's uncompressed way to describe ten pixels of black:

 

"black, black, black, black, black, black, black, black, black, black"

 

Here's a compressed way to say it:

 

"10 times black"

 

After decompression, both give the same picture, even though the later only used about 1/4th of the data.

 

As for me questioning the use of 35mm for television, it was a rhetorical question. I understand that English is probably not your first language;

 

Well, i took it as sarcastic - My first language is Finnish, sometimes subtleties get lost.

 

At first, i was about to be sarcastic on my answer too, and just say "Habbit??"... but ended up typing an essay ;-)

 

I basically am saying that 35mm is used for reasons other than its extremely high resolution, namely that you have a future-proof file with a much broader color gamut than television can ever provide.

 

Well, most of my stuff is commercials etc. material that goes the way of the dodo just a few weeks after they're done - i didn't think about archiving at all really. At that, film probably shines - both on resolution and color fidelity. Of course, if a digital intermediate is also saved, one can make safety copies of it without any generation loss for all eternity ;-)

 

I've shot a few documentaries, which will probably run for years to come - they were shot at standard def video, and archived on both DigiBeta and data on a removable hard drives. Way back when, in the early 90's i also shot one drama series... haven't heard of it since ;-)

[Erkki Halkka]

Hi,

Eki, I was wondering whether you thought it is accurate to say that you can achieve the same resolution with cheap "HD" lenses that you have on HDV camera versus top-of-the-range HD lenses that can be utilised on HDCAM camera's such as the F900. I haven't used HDV yet so I don't know, I just think it seems unlikely.

Cheers.

 

Probably not. I guess the difference should be the same as between top of the line SD camera and a MiniDV.

 

I don't actually know what camera / lens combo was used on the HDCAM projects i've done post with, but i certainly hope none of those was a high end model. My HDV material was roughly in the same ballpark with those.

 

The HDCAM footage i've worked with looked about the same as Betacam, or i.e. Dvcpro footage looked like a few years back, when looking at it 1:1 size, i mean, the same as compositing an HD frame from four Betacam frames. HDV footage looks like compositing that HD frame from four MiniDV frames. As said, different, but in the same ballpark.

 

Top of the line HDCAM's *should* look like compositing the HD frame from four top of the line DigiBeta frames... uh, i hope this didn't sound too insane ;-)