Why 4:2:0 ?

[naveenmedia]

So why does Sony use 4:2:0 for color sampling rather than 4:2:2 ? From my understanding, the latter is FAR better than the former.

How is XDCAM-HD footage for accuracy, and especially keying?

Or is there something about 4:2:0 in HD vs. HDV that I'm not aware of?

Naveen

[harddrive]

So why does Sony use 4:2:0 for color sampling rather than 4:2:2 ? From my understanding, the latter is FAR better than the former.
A lot depends on whether you're talking about an interlace or progressive system. There's a lot more logic to using 4:2:0 with progressive images, as the subsampling is then truly symetric, in a way it isn't with interlace.

Also bear in mind these are ratios, and the EX is a true 1920x1080 recording. If one job offered you 25% of the takings, and another 33%, which would you go for? But what if it was 25% of $100, versus 33% of $50........? Overall figures can be more relevant than ratios.

[Barry_Green]

So why does Sony use 4:2:0 for color sampling rather than 4:2:2 ? From my understanding, the latter is FAR better than the former.
Of course it is. It's twice as much color info.

Sony uses 4:2:0 because they are trying to cram their HD signals into the tiniest bandwidth possible. Going to 4:2:0 is just another a form of compression; they throw away half the color information.

Or is there something about 4:2:0 in HD vs. HDV that I'm not aware of?

You're not missing anything. 4:2:0 is inferior to 4:2:2.

With that said, 4:2:0 in progressive is not nearly as nasty as 4:2:0 in interlaced; interlaced 4:2:0 is hideous. Progressive 4:2:0 is better than interlaced 4:2:0. But neither holds a candle to genuine 4:2:2.

[ffaf07]

I hear that 4:2:2 is possible via HD-SDI out. But doesn't that mean that just the codec is 4:2:2, for improved color grading?

If the cam was hooked up to a computer going directly out of the HD-SDI (which is quite improbable), would one get a true 4:2:2 colorspace?

[Barry_Green]

The codec is 4:2:0. The internal processing is 4:2:2, and apparently the HD-SDI output is 4:2:2. But as it records, it subsamples down to 4:2:0, as a form of compression -- discarding half the color information from the internal 4:2:2.

Yes if you hooked up to a computer (or a DVCPRO-HD tape deck or HDCAM-SR tape deck) you would get true 4:2:2.

[SPZ]

I hear that 4:2:2 is possible via HD-SDI out. But doesn't that mean that just the codec is 4:2:2, for improved color grading?

If the cam was hooked up to a computer going directly out of the HD-SDI (which is quite improbable), would one get a true 4:2:2 colorspace?

Yes. However, this llooks a lot more probable these days. You can have a laptop record the HD-SDI signal with a Kona IO HD card, or the upcoming COnvergent Designs capture box, wich captures the HD-SDI signal to CF cards and converts it to whatever open source codec you would like...

[ffaf07]

Yes. However, this llooks a lot more probable these days. You can have a laptop record the HD-SDI signal with a Kona IO HD card, or the upcoming COnvergent Designs capture box, wich captures the HD-SDI signal to CF cards and converts it to whatever open source codec you would like...

And how much would that cost? (The cards/any necessary software)

[SPZ]

About 5000 for the CF recorder. So a canon g1 and xdcam ex, with these recorder are theoretically capable of fantastic 160 mbit mpeg 2 intraframe 4:2:2 pictures, making these 2 cameras the fixed lenses cameras to beat in therms of picture quality. A G1 goes for 7000 USD right now, if I'm not mistaken. A XDCAM EX goes for 8 000. So a package should be 12000 USD for the Canon g1 option, and 13000 for the EX.

A fantastic deal for native 1920x1080 4:2:2 160mbits mpeg2 intraframe portable recording solution, in my humble opinion.

However, the CF recorder is not available yet, so this is all theoretical, of course.

[Lenilenapi]

Can you put a Kona IO HD card in a mac laptop?

BTW what does IO mean?

[mikkowilson]

IO = Input/Output


- Mikko

[naveenmedia]

Can you put a Kona IO HD card in a mac laptop?

The Kona Io HD is not a card, but a box that connect to your Powerbook via Firewire 800. See here (http://www.aja.com/html/products_Io.html) .

[harddrive]

Of course it is. It's twice as much color info.

Sony uses 4:2:0 because they are trying to cram their HD signals into the tiniest bandwidth possible. Going to 4:2:0 is just another a form of compression; they throw away half the color information.

You're not missing anything. 4:2:0 is inferior to 4:2:2.
True if you compare like with like.

But problems come if you compare the Ex codec with DVCProHD on the basis of colourspace, as that's NOT comparing like with like. They are ratios, and meaningless without the reference.

At 24fps progressive, the EX codec records 1920x1080 samples/frame for luminance, so 960x540 (518,400) each U and V pixels recorded per frame. Corresponding figures for DVCProHD are 480x720=345,600 (for 720p) or 640x1080=691,200 (for 1080p) - so in these particular cases we see a 4:2:2 system can actually have considerably LESS colour info per frame, or only 33% more in the best case.

And in the case of the 960x540 chips used in the HVX200 and 500, much of those extra recorded pixels are wasted anyway. Pixel shift only enhances luminance resolution.

Colour space comparisons only have sensible meaning if like is compared with like.

[Lenilenapi]

Thanks, but I still don't have a full sense of exactly what this box does.

I gather it will convert an SDI 10 bit 4:2:2 signal thru firewire directly into a Mac and it will be already converted into the Apple Hi Res Codec. Does that sound right. Will it then already be a quick time file and ready to play in FCP or does FCP have to do an import of some kind first?

I am guessing then that this $3500 box would allow you to shoot green screen or anything else you were concerned about with an EX-1 that was 10 bit 4:2:2.

Its either that or lug a Mac Pro tower to the set with a Kona card. ( Actually a spare tower with a card might not be much different expense, though a bit heavier.)

Its actually not that much money if you do a lot of green screen or for a rental house to get if the EX-1 becomes very popular. Actually that's assuming that you need the 4:2:2 to get decent green screen.

What else does this thing do?

Lenny Levy

[naveenmedia]

Lenilenapi, to really get the specifics of what this box does, just call AJA or a reseller, and ask a sales person. Unless someone here knows. Having never used the box (we considered buying one, but are going with a tower and card instead), I don't know.

[Barry_Green]

At 24fps progressive, the EX codec records 1920x1080 samples/frame for luminance, so 960x540 (518,400) each U and V pixels recorded per frame. Corresponding figures for DVCProHD are 480x720=345,600 (for 720p) or 640x1080=691,200 (for 1080p) - so in these particular cases we see a 4:2:2 system can actually have considerably LESS colour info per frame, or only 33% more in the best case.
Huh? Why are you comparing DVCPRO-HD 720 to XDCAM 1080, and drawing an arbitrary and incorrect conclusion from that? (and when did DVCPRO-HD enter into the discussion at all, anyway?)

XDCAM EX 720: 640x360 = 230,400 chroma samples
DV100 720: 480x720 = 345,600 chroma samples.

XDCAM EX 1080: 960x540 = 518,400 chroma samples
DV100 1080: 640x1080 = 691,200 chroma samples.

Like for like, bro.

In any case, this is all still impossible to compare because XDCAM's pixels may or may not even be the accurate pixels for that particular position depending on how heavily the codec is being taxed at the time.

Colour space comparisons only have sensible meaning if like is compared with like.
Agreed. So let's compare 1080 to 1080, and 720 to 720. And someday let's have Sony make a decent intraframe codec so we can compare intraframe to intraframe.

But back to the original question -- there was no comparison of DVCPRO vs MPEG. The question was: why would Sony choose to use 4:2:0 if 4:2:2 is better? And the answer is? Anyone? Bueller? Well, the answer is: they do, when they raise the price tag. The new XDCAM 50mbps version is going to be 4:2:2. Why? BECAUSE 4:2:2 IS BETTER. They just cheaped out on the EX with 4:2:0 even though they were already redesigning the codec specifically for XDCAM HQ, and they had plenty of bandwidth to store the full 50mbps signal.

So the answer to the original question:
So why does Sony use 4:2:0 for color sampling rather than 4:2:2 ? From my understanding, the latter is FAR better than the former.
The answer is: they lamed out. They could have, they just didn't. They had the opportunity since they were changing the codec anyway, and they have the technology, and they have the bandwidth. They just didn't do it.

[cckid]

Thanks for clarifiyng Barry.....

[BobDiaz]

...
But back to the original question -- there was no comparison of DVCPRO vs MPEG. The question was: why would Sony choose to use 4:2:0 if 4:2:2 is better? And the answer is? Anyone? Bueller? Well, the answer is: they do, when they raise the price tag. The new XDCAM 50mbps version is going to be 4:2:2. Why? BECAUSE 4:2:2 IS BETTER. They just cheaped out on the EX with 4:2:0 even though they were already redesigning the codec specifically for XDCAM HQ, and they had plenty of bandwidth to store the full 50mbps signal.

So the answer to the original question:
Quote:
So why does Sony use 4:2:0 for color sampling rather than 4:2:2 ? From my understanding, the latter is FAR better than the former.
The answer is: they lamed out. They could have, they just didn't. They had the opportunity since they were changing the codec anyway, and they have the technology, and they have the bandwidth. They just didn't do it.


From a technical standpoint, 1920hx1080v at 4:2:2 wouldn't work well at 35Mb/s, but it would work at 50Mb/s. (35Mb/s would have too much data to compress cleanly.) Now at 1280hx720v 30p or 24p, 35Mb/s might be possible...

To me, it appears to be more of a marketing issue than a technical issue. Sony hinted of higher end models showing up at NAB. It seems likely that the higher end models will have the 50Mb/s 4:2:2 mode.

Firmware upgrades of the camera are still possible and Sony did say that an upgrade will be needed to support the 32GB cards when they come out and additional features could be added. Other than the 32GB SxS support, Sony is NOT saying what additional features might be added. So, a 50Mb/s 4:2:2 mode, might be added, BUT we can't say for sure either way until Sony says what the firmware upgrade will add.

IF Sony is waiting for the 32GB SxS card to support 50Mb/s 4:2:2 mode, it seems logical, because at that rate, 1 GB gives us only 2.25 minutes of video. Thus an 8GB SxS = 17 minutes, 16GB SxS = 35 minutes, and 32GB SxS = 70 minutes.

On the other hand, maybe Sony doesn't want to make the EX-1 camera so good, that sales of the higher end models are lost to the lower end model.

Maybe this is their ace in their back pocket in the event that other camera companies come up with improved models in the same price range....


Bob Diaz

[harddrive]

Huh? Why are you comparing DVCPRO-HD 720 to XDCAM 1080, and drawing an arbitrary and incorrect conclusion from that?
Because some people have said to me, comparing the two examples above, that "oh, it's 4:2:2 v 4:2:0, no contest" and been genuinely surprised to have the subtleties pointed out. They haven't appreciated that colour spaces mean ratios, not actual numbers. Which is why I started by saying that what you said was true - but with the like for like qualifier. I'm sure you are well aware of that - but not everybody else is. And if it isn't stressed, if like is not compared with like, *then* comments like "It's twice as much color info" in isolation are what lead to arbitrary and incorrect conclusions.

And as for DVCProHD 720 to XDCAM 1080, then that reflects the camera front ends. The Ex has 1920x1080 chips, the HVX200/500 have 960x540. The EX front end is matched to 1080 codec recording, the others can't do it full justice. Use the EX at 720 and there is considerable detail loss relative to 1080 - with the others the loss is much less, certainly in the vertical direction. What's the point of throwing bandwidth away trying to record detail that isn't there? The comparison was XDCAM 1080 to DVCProHD 720 *AND* 1080, anyway.

For interlace I fully agree that 4:2:2 is highly desirable. For progressive it may be desirable, but not at any cost, and not if it means an overall lower resolution.

[harddrive]

On the other hand, maybe Sony doesn't want to make the EX-1 camera so good, that sales of the higher end models are lost to the lower end model.
All well put, Bob. I'm actually surprised that the EX does full 1920x1080 recording versus the 1440x1080 of the other XDCAM-HD's regardless of colour space. The XDCAM dsic is a double edged sword for Sony - desirable because many users like the "consumable media" concept (whilst still being tapeless), and a millstone because of lower max data rates than solid state. (Even SD cards, let alone SxS, CF or P2!!)

I foresee interesting developments at NAB.

[zoostory]

Now let's talk about the GOP ;)

[Stevet]

Let's not ;) We all agree GOP is around due to maximizing bandwidth with limited space. Ironically, many who absolutely dislike GOP turn around and marvel their Bluray or HD-DVD player hooked to their new 1080P set.
But, I do agree we need to capture the footage with the best quality possible.

Which brings to point....
The GOP issue with the EX1 (if you really have one ;) ) SDI out will be moot in a year with Cineform and Convergent Design both offering portable solutions. I'm really interested with furture Cineform solutions. Having said that, I'm looking forward to future Sony improvements along with Red mini, and Panasonics offerings. Things just keep getting better!

[David Jimerson]

Ironically, many who absolutely dislike GOP turn around and marvel their Bluray or HD-DVD player hooked to their new 1080P set.


That's because long-GOP is just fine for a delivery medium, especially where you have fine control over the compression. It's when it's used as an acquisition or editing format that those of us who object to it start raising our hands.

I don't think too many people (except consumers) would use MPEG-2 as an acquisition format in SD when DV is available, even though you could get more into the same storage space . . . don't see why any of those reasons don't carry over into the HD world. (Yes, I know what the EX1 records; same idea.)

But hey, we all make the compromises which suit us best.

[Barry_Green]

Because some people have said to me, comparing the two examples above, that "oh, it's 4:2:2 v 4:2:0, no contest" and been genuinely surprised to have the subtleties pointed out.
But you do realize you're bringing in an argument that had nothing to do with the original question, right?

As an absolute answer: 4:2:2 is better than 4:2:0. Unquestionably.

The relativism shouldn't even involve Panasonic's codec, which wasn't even part of the discussion. The relativism that you're concerned about (IINM) is the idea of 4:2:2 at 35 megabits -- as in, should that limited bandwidth be used to encode more color resolution, or could those bits be spent better somewhere else? And the answer has to be: that's an invalid argument because -- why stop at 35 megabits? When you make a recording medium that can handle 800 megabits (or so they advertise), why stop at 35? Why not just have better?

That's the question, and that's the question we don't have an answer to.

And as for DVCProHD 720 to XDCAM 1080, then that reflects the camera front ends.
Look, your opinion, fine. Completely unrelated to the discussion at hand. Nobody brought up the HVX, nobody brought up DVCPRO-HD, nobody brought up anything like this. And I reject the classification anyway because the HVX is undoubtedly sharper in 1080 mode than it is in 720, so trying to characterize it as less really just has no place in this discussion.

So back to the topic at hand: why did Sony go with only 4:2:0 if 4:2:2 is better? And 4:2:2 is unquestionably better. So why limit it to 4:2:0? It should only be a question of bandwidth. Yet they have comparatively limitless bandwidth, higher bandwidth than HDCAM SR tape, so... there is no good answer. They could have gone 4:2:2, they should have, and they just didn't.

[Barry_Green]

Ironically, many who absolutely dislike GOP turn around and marvel their Bluray or HD-DVD player hooked to their new 1080P set.
Dude -- did you really just say this? Come on...

Long-GOP was invented as a delivery medium. Not an acquisition medium. Long-GOP is designed around the idea that the encoder can take *forever* to optimize and render out an image that is the most efficient possible, so long as the decoding happens in realtime. Multiple passes, optimizations, all sorts of things go into the front end to make the best possible output.

NONE of which happen in a camcorder, which has to process in realtime.

(and besides, those who are "marvelling" at their blu-ray or HD-DVD aren't marveling at lame ancient MPEG-2 anyway, they're probably marveling at AVC/h.264 or VC1...)

SDI out will be moot in a year with Cineform and Convergent Design both offering portable solutions.
Not sure what you mean here -- did you mean long-GOP would be moot? Because don't the Convergent and Cineform products connect through SDI?

Yes the Convergent at least (don't know about CineForm) can get you completely past the GOP issue because Convergent offers an intraframe 160mbps mode. But that box alone costs another $5,000 and the only Cineform portable recorder I know of, the Wafian, costs something like $15,000, last I checked. Are these what you're talking about or is there something else?

[Stevet]

That's because long-GOP is just fine for a delivery medium, especially where you have fine control over the compression.


Agreed! That's why I mentioned we need to capture the footage with the best quality possible.

[Stevet]

Barry, even I can't understand what I wrote! LOL

[Stevet]

I meant to write:
The GOP issue with the EX1 will be moot using the EX1 camera's SDI out with the near future Cineform and Convergent Design both offering portable solutions.


Actually, Cineform is working on a 4:2:2 portable HDMI recorder sub $2K.
http://www.cineform.com/products/CineFormRecorder.htm
Using my HDLINK SDI>HDMI, this would work.
Also, they have also talked about making an SDI version later.
Even if they upped the SDI price $1K, I'd buy in.

[naveenmedia]

The answer is: they lamed out. They could have, they just didn't. They had the opportunity since they were changing the codec anyway, and they have the technology, and they have the bandwidth. They just didn't do it.

That's sad. Particularly if it was a marketing ploy to charge more for a higher-end cam that does do 4:2:2.

HVX200a where are you?

[Stevet]

Hold tight. I'm willing to bet Panasonic is going to offer something to bounce back at the EX1.

[snowleopard]

Wow, lots of hair splitting here left to interpretation. Allow me to comment (from conjecture, yes, but just as an example):

It's twice as much color info

Wow, so the color on a camera with 4:2:2 will be twice as good as a camera with 4:2:0. Got it. Should be amazing to see how much superior it looks.

Long-GOP was invented as a delivery medium. Not an acquisition medium... NONE of which happen in a camcorder, which has to process in realtime.

Wow, that's awful. I can imagine the myriad of problems in the picture of the long GOP cameras as a result of that.

Hold tight. I'm willing to bet Panasonic is going to offer something to bounce back at the EX1.

Why should they? Their camera has color that's twice as good, and doesn't use the flawed long GOP.

Now, no one in their right mind should interpret this in such a way, but with the seemingly infinitesimal pontificating regarding this issue over mind numbing specifications, it's baffling that we delve into this in such a competitive manner instead of doing something like, oh, checking the gear out and seeing how you like it. Then going out and shooting something of quality with it.

[Barry_Green]

Actually, Cineform is working on a 4:2:2 portable HDMI recorder sub $2K.
http://www.cineform.com/products/CineFormRecorder.htm
Using my HDLINK SDI>HDMI, this would work.
Also, they have also talked about making an SDI version later.
Even if they upped the SDI price $1K, I'd buy in.
Now THAT looks interesting! That kind of product could shake things up for sure.

[Barry_Green]

Wow, so the color on a camera with 4:2:2 will be twice as good as a camera with 4:2:0. Got it. Should be amazing to see how much superior it looks.
It's easy to do -- look at DVCPRO50 vs. DV. Read some of the reports, terms like "amazing" do get used.



Wow, that's awful. I can imagine the myriad of problems in the picture of the long GOP cameras as a result of that.
You don't have to imagine, you can see the results. Normally it works fine, sometimes it's awful.


Why should they? Their camera has color that's twice as good, and doesn't use the flawed long GOP.
Agreed! :thumbsup: If they offered comparable sharpness and grain performance, it'd be an open-and-shut case.

Now, no one in their right mind should interpret this in such a way
Actually there is truth in all the statements you made, but what nobody should be doing is dragging any other manufacturer even into the discussion. Why can't a simple discussion be about what it's about, instead of trying to make it be about something else?

The question was: is 4:2:2 better? Yes. Why didn't Sony use it? No good answer. It has nothing to do with Panasonic or GOP or DVD or blu-ray or DVCPRO-HD or 720p or native camera front ends. It's a simple question: is 4:2:2 better than 4:2:0? Yes. Could Sony have done it? obviously. Why didn't they? We don't know. Should you be happy about it and try to convince yourself that there's a good reason for it? No. But if you want an EX1, it's what's offered.

instead of doing something like, oh, checking the gear out and seeing how you like it. Then going out and shooting something of quality with it.
I've tried saying that. People don't like to hear that. They want to argue numbers.

I'm at least trying to keep the numbers at a usable scientific level, instead of going into the same pointless pixel arguments that have been happening for the last three years.

[Noel Evans]

Now THAT looks interesting! That kind of product could shake things up for sure.

Man, if they whacked an SDI In on that Id almost be tempted. Just go straight to cheap CF while I wait for p2 to fall from its dizzying heights :P

[Stevet]

Well, as everyone knows. 4:2:2 is possible from the EX1 via SDI and then using a compression format of your choice.

This is only ONE aspect of producing a decent image. Rez, image latitude, NOISE, sensitivity all add up to REAL image quality.

Barry has made this point himself. I amazed on how many jump on the 4:2:2 bandwagon without thinking about anything else.
With SDI solutions soon to be released, it's not much of a stance.

There's a lot more that must be considered. It's almost like fitting expensive RIMs on a 75' Ford Pinto and expecting highend performance.

[Stevet]

Man, if they whacked an SDI In on that Id almost be tempted. Just go straight to cheap CF while I wait for p2 to fall from its dizzying heights :P


Read my post again. According to what I've been reading at the "other forum", Cineform plans on rolling out the HDMI, THEN the SDI later on.

[sundance44ANCE44]

I Think Its Time For Me To Dust Off My Old Kodak Brownie And Load It With Some 620 Bw Film, This Digital Thing Is Getting Very Complex, What Happened To The Simple Life????????????

[Stevet]

I Think Its Time For Me To Dust Off My Old Kodak Brownie And Load It With Some 620 Bw Film, This Digital Thing Is Getting Very Complex, What Happened To The Simple Life????????????

LOL, that's for sure!

[snowleopard]

I've tried saying that. People don't like to hear that. They want to argue numbers...I'm at least trying to keep the numbers at a usable scientific level, instead of going into the same pointless pixel arguments that have been happening for the last three years.

I feel your pain. It's gotten so whacked it's as if DVXuser needs it's own specific forum where people can compare/argue/bicker and anything else about tech talk on cameras ad infinitum, and leave the rest of the site to more meaningful discussion.

[Noel Evans]

Read my post again. According to what I've been reading at the "other forum", Cineform plans on rolling out the HDMI, THEN the SDI later on.

Yes well, Ill certainly keep an eye out. Direct to disk recording in SDI??????? YES PLEASE!!!!!!!!!!!

[Stevet]

I'm a real fan of the Cineform codec.
The ability to capture 4:2:2 to Cineform on a portable device has been a dream of mine for quite a while.

[naveenmedia]

I feel your pain. It's gotten so whacked it's as if DVXuser needs it's own specific forum where people can compare/argue/bicker and anything else about tech talk on cameras ad infinitum, and leave the rest of the site to more meaningful discussion.

Hey, I didn't mean to start an argument, I was just asking questions as someone who's not familiar with the technical issues, particularly on the acquisition end of things. No harm intended! :)

I got into video through the back-end: education in graphic/web design, job with production company doing graphics for post, moved into editing, then got focused on workflow issues that led me to acquisition (i.e. shooting).

So I have a lot of basic tech questions and I appreciate all the help from those here at DVXUser who seem so willing to share! This site is a gem of a resource, and much better than some other forums, where people are often non-responsive or cocky know-it-all's.

My thanks to Barry Green, Stevet, Philip Bloom, puredrifting (Dan), MattinSTL, and any others I know I'm forgetting for the massive amount of good info I've gotten from this site in the last few weeks alone. I've tried to contribute as much as I've been able, and hope to offer more in the future.

And to the specifics of this debate, different cameras will be better than each other in different areas, some will be just "better" overall, the only way to know is to actually try the gear. I wholeheartedly agree!

But it helps to at least have a handle on basic knowledge of what's better, at least on paper, to help evaluate any new product and to get the best results, which is why I asked.

Naveen

[Barry_Green]

I feel your pain. It's gotten so whacked it's as if DVXuser needs it's own specific forum where people can compare/argue/bicker and anything else about tech talk on cameras ad infinitum, and leave the rest of the site to more meaningful discussion.
Agreed. Problem is, the tech talk is like 80% of the discussion here, and "the rest of the site" (excluding the fun nonsense in the cafe) is pretty minimal. I'd love to see more participation in the screenwriting and directing and cinematography forums, but those sections don't get nearly as much traffic.

[Barry_Green]

Hey, I didn't mean to start an argument, I was just asking questions as someone who's not familiar with the technical issues, particularly on the acquisition end of things. No harm intended! :)
There is no harm done -- our site excels at explaining the issues, and you asked a specific issue (and this is kind of why I've taken a hard line in this discussion on trying to keep the issue centered on what you asked, instead of letting it get derailed into some manufacturer vs. manufacturer debate).

A simple understanding of 4:2:0, or long-GOP, or rolling shutter, or CCD smear, or backfocus, or any of the other myriad of technical issues we face, is what many of our users need and search for. And we're glad to help explain these items. Your question was entirely appropriate for this forum.

While it'd be nice if we got more participation in the art & craft sections, a large part of this forum's value is in our helping people to understand those things that they don't currently understand.

for the massive amount of good info I've gotten from this site in the last few weeks alone. I've tried to contribute as much as I've been able, and hope to offer more in the future.
That's exactly what we're about here. We've had many who started as relative newbies and who have shared much of what they've learned. We like that.

[Stevet]

Agreed!

"Can't we all just get along". I'd bet if we all got together over a few beers, there would be FAR less debate and more creative discussions. I really believe most of this stems from having to write your thoughts in a couple sentences. It really makes it hard to convey we all just want the same dang thing.

Also, which has been brought up in this thread and a million others, it's really how we use these tools. All of these cameras ar very capable of producing great images.

Having something worthy shooting is 80% of it. I could take a 200K camera into my kitchen, shoot a quick round. I'm sure I would be very uninterested in the footage. Yep, there's my kitchen.... boring....

We all certainly agree on having decent images for composition.

[nyvz]

So wait, now wouldnt the HVX have a maximum theoretical useable color resolution of around 640x540 since one cannot get more than 540 lines of vertical res in one color channel from a 960x540 single color ccd even if the color channel is recorded as 640x1080? and wouldnt this resolution, where the ccd resolution is the limiting factor vertically and codec is limiting horizontally, be less resolution than the ex1's 960x540 color resolution which is a resolution limited by the 4:2:0 sampling in the codec? furthermore, wouldnt the the 4:2:0 of the ex1 be superior even further since 2:1 scaling (1920x1080 chip to 960x540 output) is less likely to create artifacts and soften the image than 1.5:1 horizontal scaling (960x540 chip to 640x540 usable output resolution). not to mention a 960x540 codec is more likely able to represent 960x540 resolution than a 960x540 ccd is able to capture 960x540 actual resolution. does that make sense? in this way, would it be reasonable to say that despite the alure of 4:2:2 dvcprohd in the hvx, the ex1 is more likely to produce color channels with more useable resolution in most situations?

[David Jimerson]

So wait, now wouldnt the HVX have a maximum theoretical useable color resolution of around 640x540 since one cannot get more than 540 lines of vertical res in one color channel from a 960x540 single color ccd even if the color channel is recorded as 640x1080? and wouldnt this resolution, where the ccd resolution is the limiting factor vertically and codec is limiting horizontally, be less resolution than the ex1's 960x540 color resolution which is a resolution limited by the 4:2:0 sampling in the codec? furthermore, wouldnt the the 4:2:0 of the ex1 be superior even further since 2:1 scaling (1920x1080 chip to 960x540 output) is less likely to create artifacts and soften the image than 1.5:1 horizontal scaling (960x540 chip to 640x540 usable output resolution). not to mention a 960x540 codec is more likely able to represent 960x540 resolution than a 960x540 ccd is able to capture 960x540 actual resolution. does that make sense? in this way, would it be reasonable to say that despite the alure of 4:2:2 dvcprohd in the hvx, the ex1 is more likely to produce color channels with more useable resolution in most situations?

Whatever the math, this misses the point of the thread.

Imagine the EX1 with 4:2:2 instead of 4:2:0. It would have twice the color info that it currently has. What the HVX or DVCPRO does doesn't matter to that point.

[harddrive]

But you do realize you're bringing in an argument that had nothing to do with the original question, right?
No - because whilst you may understand the wider issues, many don't, and think ANY 4:2:2 system is better than ANY 4:2:0 system. That's not true, and bringing in the wider differences, and using DVCProHD resolutions as an example to illustrate the point, I would call valid.
As an absolute answer: 4:2:2 is better than 4:2:0. Unquestionably.
With the qualifier "like for like" I agree. As a blanket statement, it could be misleading.
And I reject the classification anyway because the HVX is undoubtedly sharper in 1080 mode than it is in 720, so trying to characterize it as less really just has no place in this discussion.
Err, I don't think I said anything of the sort, look again before dismissing it.

I actually said: "Use the EX at 720 and there is considerable detail loss relative to 1080 - with the others the loss is much less, certainly in the vertical direction." which clearly implies my belief that the HVX200/500 are sharper in 1080 mode than 720. How much of this is due to 720 DVCProHD downsampling to 960 I don't know - it would be interesting to see the difference between the HVX 1080 mode and a 720 mode recording the full 1280x720 raster, rather than 960x720.

But this isn't a number crunching argument anyway. We've seen very good examples of 1080 images from the HVX, the EX and others, and the EX was unarguably much sharper. The conclusion I draw is that the overall luminance resolution is way more important than any 4:2:2, 4:2:0 arguments.
-- look at DVCPRO50 vs. DV. Read some of the reports, terms like "amazing" do get used.
I believe you are referring to reports within the US. I don't disagree with the conclusions - but they are therefore comparing 4:2:2 with 4:1:1, not 4:2:0, and there's a world of difference. DVCpro50 also has much milder overall compression, so the 'amazing' difference isn't solely down to colour space anyway.

In 50Hz countries 4:1:1 only exists at 25Mbs within DVCPro, and that's far less common than DVCAM. The very widespread use of 2/3" DVCAM here for broadcast use (even within an interlace system) tends to make me feel that whilst noone should claim 4:2:0 as good as 4:2:2, the practical differences are less than sometimes made out.

[Barry_Green]

harddrive, I'm being patient but you're bordering on trolling with this. You seem so hell-bent on discrediting anything and everything Panasonic that you're flinging it into a thread that had nothing to do with Panasonic. Why not just give it a rest?

If the question had been "is Sony's 4:2:0 as good as Panasonic's 4:2:2 from the HVX" then maybe you'd have a leg to stand on. As it is, you're dredging up numbers in a vain attempt to discredit Panasonic's efforts, in a thread that had nothing to do with them.

So let's try again, and let's try to stay on track: is 4:2:2 better than 4:2:0? Yes. Absolutely, unquestionably, without a doubt. You will never, under any circumstances, ever find an uncompressed video system where the engineers say "y'know what? Let's just subsample to 4:2:0 'cause I think it looks better." That won't happen because the very notion is patently absurd. If you want to argue the particulars of tradeoffs involved in compression algorithms, that's a different discussion. If you further want to muddy the waters by bringing in long-GOP unfiltered vs. intraframe prefiltered, you're just confusing the issue.

For all you know, the original poster could have been talking about 4:2:2 from DigiBeta. Or MPEG-IMX. Or HDCAM-SR. Or BetaSX. Or, basically, any and every professional format -- they're almost all exclusively 4:2:2, only HDCAM differs (it's 3:1:1, which is still a darn sight better than 4:2:0).

So, back on topic: Sony could have made the EX1 4:2:2. It would have been better had it been 4:2:2. They didn't do it. We don't know why. End of story.

[ffaf07]

/thread.