HD Erosion
By itself, a Sony EX3 might be a great camera but it’s not HD broadcast quality. Not in the U.K, not for Discovery Channel, not for Television New Zealand.
The HD technical delivery standards documents that explain this are drawn up by the broadcasters themselves, perhaps so they will never have to hear the “it looked good when we shot it” defence of programmes that turned out to look inferior by the time they were watched on the average home’s television.
If the ordinary viewer is to see the quality they can reasonably expect from a programme marketed as HD, the acquisition formats need to have sufficient quality headroom so they don’t fall apart when they go through all the processing, conversion, compression involved in a broadcast and transmission chain. That’s before you get to the decoding and processing that take place within television receivers that may themselves be struggling with variable signal quality.
The HD standards and quality issue has been stirred up recently within the television camera community in New Zealand because of a series called North that was commissioned and broadcast by Television New Zealand (TVNZ), the state owned broadcaster.
Presented by Marcus Lush, the prime time documentary series is a showcase for some of the North Island’s ‘gorgeous’ natural and urban landscapes. And it’s popular; the final episode aired not long ago, attracting ratings only a few thousand shy of TVNZ’s flagship One News.
HD Prestige
Like many other broadcasters around the world, TVNZ broadcasts HD and has invested heavily in an HD infrastructure, but many programmes are still not acquired in HD. To be fair, TVNZ is upfront about all this, and only genuine, native HD programmes get the HD logo in programme guides, programme trailers and the credits.
But according to TVNZ they relaxed their own standards when it came to North.
Spokesperson Megan Richards explains that the series was commissioned as an HD programme but shot on a Sony EX3.
“While it doesn’t meet the letter of the law of a published minimum spec for HD, the resolution is high enough to qualify for HD,” says Richards.
But for many cameras falling into the EX3 price bracket, resolution is not the area of concern; the codec is.
Sony EX3 cameras record 4:2:0 long GOP codec with a data rate of 35Mbps which doesn’t meet TVNZ and other international broadcasters’ criteria for what qualifies as HD.
“It is fair to state that while North did not meet the 4:2:2 standard it was well shot, lit and post-produced and that any quality loss relative to 4:2:2 was minimal,” says Richards.
“This is not always the case however, and the decision to accept it as HD was a one-off and should not be seen as a precedent.”
But with continual budget squeezes, one so called non-precedent can easily lead to another – and this could happen if TVNZ looked at North and came to the conclusion that 4:2:0 35Mbps looked just fine for a prime time HD show after all. It might even have them thinking that they had set the bar too high in the past.
Mistake
A Sony EX3 with letus and Nanoflash, photo courtesy of Ben Ruffell
But that’s not entirely right, as CREWS.TV members subsequently found out. Director of Photography Jacob Bryant, posting in a CREWS.TV forum, said that North was shot on a Sony EX3 but the recording was via the camera’s HD-SDI 4:2:2 10 bit output to an off-board nanoFlash recording 100Mbps MXF 4:2:2 HD.
This is a fairly common work around that propels the Sony EX3 camera past the minimum 50Mbps data rate well into the acceptable range of TVNZ and other international broadcasters’ published quality standards criteria.
As it happened, Bryant also enhanced the look of the show with Zeiss ZF lenses on a Letus lens adaptor, giving a 35mm style depth of field effect associated with larger sensors.
The EX3′s 1/2 inch sensors meet the TVNZ specifications and the U.K. standards too, although some standards documents state that most cameras with sensors under 1/2 inch do not qualify as HD.
It is unknown if TVNZ quality control systems would have noticed a problem during ingestion if the footage was indeed originated in 4:2:0, and in any case by then would be little that could be done about it, other than removing HD badge from marketing materials.
“In essence we operate a trust model where we rely on the integrity of the production company,” says Richards. “This is a small market and they wouldn’t want to jeopardise their relationship with TVNZ by falsely claiming something was HD when it was not.”
Issues remain
Given these facts, whether or not North deserves to be marketed as HD turns out to be a fuss about nothing, because although the camera doesn’t qualify by itself it was beefed up with some good recording kit for the shoot.
But it does seem TVNZ is willing to drop the standards if they prove inconvenient, and this leaves the underlying issues simmering for another time (and some other stories).
At the heart of it all are two questions: What is the acceptable standard for something to be commissioned and marketed as HD? What will be implications if those standards are eroded?
Typical standards documents get revised from time to time but that doesn’t mean the standards should drop, in the rest of the world outside broadcasting, new standards usually get tougher.
The current TVNZ document mirrors overseas broadcaster documents, particularly those previously issued by the BBC. It’s called Technical Standards and Documentation Guide for Television Programme Delivery– TVNZ Standard S57-4-2009 Production. It is dated March 2009 and engineering sources at TVNZ say it is under revision at the moment – the reason we have not posted it.
According to Richards the document is not intended to be a prescription written in stone in any case.
“The standards document is the guide. Variation can be negotiated, but only for specific circumstances and where appropriate to the particular programme and genre,” she says. ”It is subject to change as technology arrives and when specific productions operating in unique circumstances require.”
At least TVNZ are up front about the issue. There is another approach that some other networks adopt – which might avoid the issue in the short term, but doesn’t make it go away. In fact it may accelerate the erosion of HD quality, and in turn erode the value their channel’s brand.
The approach is, of course, to have no standards.
Photo of Sony EX-3 courtesy of Ben Ruffell www.ruff.co.nz
This website is brought to you by the support of the CREWS.TV membership and its member sponsors
The EX 3 is a preliminary device and was never HD but through being able to record 100mb 4.2.2 over HDSDI to NANO has pushed it into an HD realm. Granted the sensor size does not meet HD standard. The issue of what is true HD or not will become irrelevant as technology changes and we can already see that with the recent release of current cameras so I dont believe HD is being eroded but becoming more accessible to low budget productions. If I was given a choice between the aesthetic of the not regarded by some EX 4.2.2 100mb and letus to the sterile look of the XDHD I would still go with the the Letus and a decent set of lenses. Wouldn’t you?
If anything it shows how complicated the newer technologies have become. Nothing in the TVNZ spec makes mention of the sensor size, or specific models of camera. What is mentioned is codec types and bitrates – and in that context 100Mb/s 4:2:2 Interframe is absolutely “HD”.
So an EX-3 isn’t HD on it’s own, but then with another recorder it is. And then more confusing is the fact that sometimes it could be accepted as HD on it’s own – as TVNZ’s mistaken statements here demonstrate.
I am a big fan of XDCAM HD422 as a format, and there are many cases where a shoulder-mount ENG camera is going to be a LOT more practical than a camera like the EX-3 with a lens adapter and extra lenses. Horses for courses they say, and there are a lot of horses and courses.
This is a really poor article Peter. If your intention was to further confuse the issue well done you did it.
Why did you let Megan Richards the TVNZ spokesperson give you totally incorrect information, then publish it ?
“It is fair to state that while North did not meet the 4:2:2 standard it was well shot, lit and post-produced and that any quality loss relative to 4:2:2 was minimal,” says Richards. “This is not always the case however, and the decision to accept it as HD was a one-off and should not be seen as a precedent.”
Except of course it was shot 4:2:2.
This would be the time to inform your readers that the EX records 4:2:0 when compressing to the onboard SxS card, yet delivers 4:2:2 out of the HD-SDI output which the Nano recorder uses.
Then you go on to say:
“…one so called non-precedent can easily lead to another – and this could happen if TVNZ looked at North and came to the conclusion that 4:2:0 35Mbps looked just fine for a prime time HD show after all.”
But of course North wasn’t 4:2:0, and it wasn’t 35mbs.
Obviously the entire point of using a Nano was to meet the 4:2:2 and 50mbs standards. So these technical standards are not what is in dispute here.
You seem to be suggesting that North is an example of an erosion in broadcast standards and unacceptable for HD. When clearly the production went to some trouble to meet HD broadcast standards.
As you point out 1/2 inch sensor is OK with TVNZ specs, 4:2:2 is OK and 50mbs is OK. So what exactly is your point about North ?
This article is not good enough and only brings confusion to the topic. I expect a higher standard from NZ crews when it publishes content like this to an open audience on the web.
I disagree, North simply raised questions about HD. Questions that in reality nobody knew the answers until now.
Megan’s statements simply opens the field; even without the nano, it would be acceptable. That is pretty clear to me, thus the decision to leave it in.
In the end as Peter says its a fuss about nothing because the production not only met the standards but exceeded them.
As new cameras and work flows enter the marketplace at better price points and various quality trade offs, this whole debate becomes the foundation to some pretty serious decisions not just in NZ but globally.
Tech checks, exceptions and even taking a minimum standards document as a guideline are all new facets of HD production that has ramifications on how we view the broadcast HD realm.
We have a whole series of upcoming articles about understanding technical broadcast standards, I trust they meet and exceed the benchmark that you expect from us!
Thanks for your comments
Actually Yves you should no the answer to this as I posted on a thread two weeks ago on NZcrews the shooting specs for north in a far to similar discussion.
When I said now, I meant it figuratively. Your information was passed along to Peter after he spoke to TVNZ. I appreciate how this could be confusing but the story clearly states the discrepancies and its implications.
We looked into this simply to gain clarification. Its not a case of one format versus another because we now live in a world of a multitude of tools for all types of projects.
North is a beautiful program and nobody here is saying that it’s aesthetic is eroding anything. In fact one would say totally appropriate.
But it raises issues about the merits of HD and codecs and bitrates as you have gone down a great path (however unwieldy) to achieve a great look.
But there is confusion out there as Dylan says, manufacturers, broadcasters and individuals whom all have different ideas, let alone agendas. You mention yourself that 1/2 inch is not HD and in fact it can,if be paired with the right codec – which you have acknowledged. Where is that line drawn? 100mbs? 35mbs? 24mbs?
Me personally, I don’t care I just want to know so I can make an educated decision in what tools I use for what project. I have my own ideas as to what looks good when it comes to sensors and bitrates and so does everyone else.
You asked me what I would use? On your project, I think you chose the best option at the time to achieve the look you set out to achieve. Today there is a lot more choice and they aren’t so clear. Would an FS-100, AF-100, F3 or even the 5D mk2 pass this tech document or would it be an exception?
I thought the whole point of this article Yves was to say that North is Eroding HD standards. Isn’t that what the article is saying ?
Not at all. Its about eroding standards at TVNZ after investigating North.
Well perhaps you should have this clear in the article. The title is HD erosion. The ONLY example used is ‘North’.
Where are the examples of the 4:2:0, 35mbs shows that TVNZ have passed for HD broadcast ?
Please list them right now because you seem to be saying that there are HD branded TV shows on TVNZ now that have been shot with these lower specs. And that is certainly something I would like to know about. And its obviously something that should have been included in an article about the erosion of HD standards in this country.
All this confusion simply points to the fact that this is a badly written article.
Hey Mat, once again, I disagree, the facts are all there, they have been verified and confusion could come by skim reading and perhaps even being hung up on a few details.
As a result of your comments I have run this by a few journalists friends who had no problem understanding the article let alone grasping these complex concepts.
The fact remains that the info contained here is important for us as producers/cinematographers to understand where our boundaries lie.
If there is one thing that is completely clear is that TVNZ have a sliding scale, based on content and exceptions and that is what you should take away.
Regarding north, I have been in contact with Jake and we hope to construct an article with his POV in mind, because his decision choices, in light of the Technical Standards document is interesting, one we as TV makers do everyday, either conciously or by default.
I am happy to speak to you over the phone and walk you through the article point by point, to understand your points clearly and identify exactly where your confusion sits. Once again thanks for your feedback.
If you are to write and article based around a specific piece of work I would expect that person to at least have the nous to get his facts rite. Maybe even call the person who shot it would be a pretty good place to start. The argument is healthy if the information is correct other wise its wasting our time and confusing.
If you read the HD specs then “no” 1/2 inch would not pass but how on earth! do you in the “specifications department” know how large one mans sensor is? Im pretty sure given we are seeing 5D being passed and broadcast as HD that the standard is open to interpretation so maybe we should enjoy the freedom of choice and get on with making images that hopefully people like to sit down and watch. And yes of course each project requires some thing different.
Current UK/BBC specs:
“2.7.1 Non HD-material: … Most cameras with image sensors under ½” …”
TVNZ 2009 Spec: “TVNZ’s definition of HD also specifies that content should be shot on 1/2 inch (or larger) sensors with HD 4:2:2 processing. Cameras with sensors under 1/2 inch and 4:2:0 processing (e.g. HDV) are not considered HD. ”
Current Discovery spec: no mention of sensor size.
So Peter why does your article not clearly state that in fact North meets all the technical specifications as you understand them ?
Yet completely to the contrary the whole article uses North as the one and only example of the current Erosion of HD standards.
The whole thing just makes no sense.
Next to photo of EX3:
“North was shot on a Sony EX3 but the recording was via the camera’s HD-SDI 4:2:2 10 bit output to an off-board nanoFlash recording 100Mbps MXF 4:2:2 HD.
This is a fairly common work around that propels the Sony EX3 camera past the minimum 50Mbps data rate well into the acceptable range of TVNZ and other international broadcasters’ published quality standards criteria.”
You can wave the tech spec requirements till the cows come home but to me the bottom line is the image. Does it look appropriate and in context for the feature, doco, etc? Very rarely is anything shot clean in features; with diffs, Pro Mists, defractors, etc. always degrading the image in some way. The grain (noise) and reduced exposure latitude of digital cameras like the Sony EX3 can be a creative element to help tell the story.
So who’s to say what’s acceptable or not, the engineers looking at a scope will offer a definition based on measurable technical parameters. I’ve ssen enough old films which I would consider very suspect for being classified as HD with today’s standards, but you never hear of them being rejected for broadcast.
Let’s be realistic and get back to what cinematography is all about, story telling with images and leave the specs to the techs!
The whole article sounds like “sour grapes” to me. Is it possible someone is bitter because someone else can do just as good a job if not better with less expensive equipment???? I am lead to believe the BBC has just purchased a large quantity of Canon F305′s…. and its a 1/3 inch chipset….
GMB, I can see your point it coming across that way but its not. Your point is however correct, what is the BBC telling us? Are 1/3 chipsets acceptable? To the naked eye of course it looks good, who is the gatekeeper here? Is there a gate? The Tech documents are pretty comprehensive Nat Geo, Discovery, BBC, TVNZ so on and so on.
Are we to dismiss these documents because it looks good to the eye? If so no worries, then we can just go that path.
This is right on. There has to be a standard and a pretty damned high one. Each step in the process seems to beat this stuff up more and by the time they push it through a cable it can be downright ugly. I’m in no way an engineer or tech guru but the idea that we can throw a picture out there and say “hey, it’s 1080p of course it’s HD” is perilous thinking and short sighted. I’m with Yves here.
At the end of the day it just has to look good for the client and for the viewer…. If it looks half decent most networks will take it to try and live upto a “HD promise” to the viewer.. Unfortunately here in Australia FOXTEL compresses that crap out of everything no matter how good it looked to start with and only if you get the HD channels do you stand half a chance of watching anything with decent picture quality. Not to mention the % of programs that are shot high end SD and output as HD.
I am also informed that 720p could likely be adopted as the HD standard for most networks worldwide….
I think that’s the frustration. “This is good and thats not and this might be.” I just worked with a young DP who made a few mistakes that caused a huge post produciton expense and his attitude was that “they don’t know the difference.” But I do. I want more from all of this. I want to know that I delivered the highest possible standard and lived up to my comittment to try and be excellent.
I think what confuses this is the talent and skills Jacob brought to a show like North.
There is a mile of difference between someone experienced at shooting using any format and the office runner/producer picking up the latest flavor of the week camera and hosing stuff down with it.
There seems to be a halfhearted attempt by programmers to control quality by tech specs instead of making sure the DOP assigned to a project is someone who knows what they are doing and trusting them to use the right tool for the job to give the best quality on screen for that show.
I would point out that here in the UK for the BBC, it is not possible to deliver Super16mm with a 2K scan finished at HD and call it HD without some real arm twisting.
While there is confusion over what is considered HD, in practice the bar is set quite high.
Interestingly the BBC has just ordained the AG-HPX370/1/2 as an HD production camera. This is despite it being 1/3″, but because it is 10bit 4:2:2 100Mbps. So it now sits alongside some heavy hitters including the likes of the AJ-HPX3000 and F900′s etc. They have also listed the AF100/1/2 as a specialist camera providing it records to an external 4:2:2 recorder. So from this we can conclude that the BBC at least realise that sensor size is no longer an indication of HD performance.
Goodness. Maybe we should just concentrate on the shoot day tomorrow.
Im off to charge some batteries and download some rushes. Happy shooting
The one thing this story does not do is clearly state anything.
We take on board your comments. Thanks.
For what it’s worth and if anyone is still reading this thread, I fully agree with Mathew Knights comments.