Thanks a lot Glenn. I'll start reading this right away... :)
Lars

I'm a bit confused here... ;)

1 - I let Cineform Neo Scene convert my 5D2 footage into an AVI. I drop that file onto the time line. I watch the histogram: info from around 16-235.

2 . I let Vegas make an AVI export and then re-import that on to the same time line as the CIneform clip. I look at the histogram. Now I see image info from 0-255.


Let's assume I want to add text onto these scenes. Using the default text generator settings.

Then the text will be 255 white...

Text will now be whiter than the whites on the Cineform clip.
And it will the same white as the whitest on the Vegas AVI clip.

If I want to render to something that should be broadcasted, broadcast engineers would likely want 16-235 on their disk/tape. That means I have to compress even more, to get the text down from 155 down to 235... Then the image will be reduced even further down, below 235 - which would be very wrong....

Text outlines are sometimes black... so 0 black would be lifted to 16. Then the 16 in the Cineform video would be lifted to 32... Which would be wring too.

For video productions that I would *only* use on the Internet or on a computer - 0-255 may be just what I want.

For broadcast I may want 16-235.

So why can't I get the CIneform conversion to be 0-255, and then when I render the project, then *I* decide exactly what my output dynamics of the project should be?

I may have misunderstood something here. I need to read up on this, but please help to clarify this level / dynamics mystery...

I add the Cineform clip to my time line.... but what then...? Any settings in Vegas I need to do.... And if I *want* it 0-255, just like Vegas conversion from my 5D2 footage...



Best & thanks in advance...
Lars

You need to pay attention to the units I think. There's a difference between RGB and Y'CbCr.

For broadcast, you want levels to be between 16-235 for Y'. However, there is no way to directly see Y' values from Vegas. So you need to make sure you are sending the right RGB values to the codec, which will convert the values into Y'CbCr.
So you need to convert all your levels into whatever the final codec wants to see / expects.

RECAP:
1- convert everything into either studio RGB or computer RGB levels.
2- when rendering, apply a studio <--> computer RGB conversion if necessary depending on the codec.
You need to manually handle 1 and 2.

Hi Glenn,

Thanks for your advice, but I need to know in detail how to set this up...
---------------------

Glenn: "You need to pay attention to the units I think. There's a difference between RGB and Y'CbCr."

Lars: So what excatly do I do about this?


Glenn: "For broadcast, you want levels to be between 16-235 for Y'. However, there is no way to directly see Y' values from Vegas. So you need to make sure you are sending the right RGB values to the codec, which will convert the values into Y'CbCr."

Lars: Are you talking about the conversion process that takes place in CIneform Neo or when I'm exported my finished project. Or soething in my project set up in Vegas while editing?

Glenn: "So you need to convert all your levels into whatever the final codec wants to see / expects."

Lars: Exactly what level conversion, how, where and when do you mean here...?

Glenn: "RECAP: 1- convert everything into either studio RGB or computer RGB levels."

Lars: When and how. I don't find any settings in Cineform Neo that delas with this. Or do you mean in Vegas? How?


Glenn: "2- when rendering, apply a studio <--> computer RGB conversion if necessary depending on the codec."

Lars: But then that is clearly going to affect *BOTH* the footages that I have converted with Cineform Neo (16-235) and text and FX that will have produced 0-255 signals. How can I render so that parts of my edits are adjusted but not other parts?? And I surely want to see *while editing* what it looks like... So I can't sit and work with parts being 16-235 and other stuff 0-255....

Glenn: "You need to manually handle 1 and 2."


Lars: Ok... but how...?





Thanks in advance for your continued help in carifying the mystery...
Lars

Add a Levels or Color Corrector FX and use the appropriate preset.

Glenn:
"Add a Levels or Color Corrector FX and use the appropriate preset."


Lars: Well, that means expanding the dynamic range back to where it was before. Like wanting Cineform to do what Vegas AVI rendering does: preserving and not changing the 5D2 original dynamic range ( 0 - 255).

a) Doing the change you suggest in 8 bit mode on all my footage will not be ideal from a quality point of view... And switching project to 32 bit floating point will lower the frame rate, and the whole point in converting the original footage to get better frame rate is gone of course... ;)

b) Having that FX plugin re-establishing my full 0-255 while working will lower fps-performance while working isn't good. Always having to work live with editing work and have a plugin correcting levels, always to the same setting feels wrong...

c) Not having that FX inserted will force me to look at an image quality that isn't representative of the final result. Adding text etc. to an image where the levels aren't right is a bad idea.

d) It isn't possible with the plugins to exactly match the dynamic alteration that the Cineform 0-255 > 16-235 has done. This means that my footage will have a slightly "non original footage look" and thereby resulting in an undefined factor in my productions - not ideal... The exact curve of my 5D2 I don't want altered without knowing how/why etc...


Any other ideas Glenn? Are there for instance any real reliable setting in Vegas that will interpret 16-235 input material as 0-255? Or someting like that...



Thanks for your kind help
Lars

Sorry to interject but this doesn't seem too complex to solve.

If Cineform is making the 5D2 footage 16-235 i.e. "regular video", then make your text etc match that. I never use the defaults in the text generator, I adjust black to 16 and white to 235. Maybe even make my white a tad below that even.

What I'd be more worried about and check carefully is if the CF codec is clipping what it might think are illegal levels.

Bob.

Hi Bob!

Not at all - feel free to join ;)

Well, for video played only on computers and the web 0-255 may not be bad. It may actually be better.

I wirk a lot with graphics and stills and varous material and compressing / limiting dynamics to 16-235 may not be a good idea.

16-235 is only good for me when I *know* a broadcaster requires this. So I rather use the full, fresh dynamics and only make corrections based on artistics needs... *THEN* change to 16-235 when my client requires that.

Now if the CIneform had not oputputted 16-235 only it wouldn't be a proble for me.

Regarding the way the do 16-235 from 0-255. It is quite clear they don't clip the whites or blacks. They seem to make a proper compression of the dynamic range. So no details are lost. But re-expanding it messes with the bits and will (in 8 bit) surely provide a quality degradation. So I don't wanna do that.

Perhaps it is CIneform? The should have a checkbox in their Neo Scene for 0-255 or 16-235.

There's a lot speaking for 0-255 when in the computer world only.



Best
Lars

I'd be more concerned about Neo's 4:2:2 chroma sampling than what you're worrying about if you're sweating so much over perfection. I'd also mention that in the world of video nothing that I'm aware of uses the full dynamic bit range. Cineon cuts off a lot more than 8bit video does and for much the same reason.
Given that Neo Scene is 10 bit then leaving a bit for over / under makes sense, ideally you should be running this in a 10bit pipeline I think or in the case of Vegas 32bit float. but that raises other issues as you've noted. You can edit in 8 bit and switch to 32bit for final render though.

Bob.

Lars...

You'll drive yourself crazy with this as long as you try to work with Vegas. Other NLE's don't work this way. IMHO, Vegas is FUBARed when it comes to color conversion. And the reason Cineform behaves the way it does is because Sony mandated this to Cineform before they would agree to use Cineform.

I flushed vegas down the toilet over exactly this issue. And the local pundits just make the whole situation even more confusing.

Hi Bill,


What other editing application would show these Cineform files as 0-255 instead of 16-235 as they now show up as in Vegas Pro 8?


Best,
Lars

Your question seems to imply that there is a simple answer to a very complicated situation. In my experience, it's more appropriate to ask which application allows more flexibility when importing. The Cineform codec allows the user to choose whether they want ITU 709 or Video RGB. Unfortunately, with Vegas, the user choice is over-ridden by the software to default to Video RGB. The blanket assumption is that ALL input needs to be remapped to video RGB. Vegas adds to the total confusion by introducing their funky 32 bit floating point mode, which introduces a whole raft of other problems.

The only application that has an approach that I can wrap my mind around is Avid Media Composer. In Avid, when you import, you have a choice of Studio RGB or BT 601/709. The choice you make is dependent on what the color range is for your incoming footage and what color range you want out.

Edius also has a more rational approach to handling this problem than Vegas' catastrophe.

Regarding the way the do 16-235 from 0-255. It is quite clear they don't clip the whites or blacks. They seem to make a proper compression of the dynamic range. So no details are lost. But re-expanding it messes with the bits and will (in 8 bit) surely provide a quality degradation. So I don't wanna do that.

I wouldn't worry about quantization error if your footage has noise in it. It's only potentially an issue if you are working with computer-generated material. You simply won't see the problems and therefore it's not a problem. Try this:
Add repeated studio <--> computer RGB conversions, i.e. convert your footage repeatedly. Click the half-moon icon in the video preview window (right click it to bypass video FX and select all) to toggle between FX applied and FX not applied.
Do you see a difference?

----
It doesn't have to be difficult.
A- The simplest and fastest approach is to work in 8-bit mode for Vegas.
B- I believe my article clearly lays out what you have to do. Convert everything into studio RGB and work that way.
Ignore the video preview as far as color goes if you convert everything into studio RGB.

But it doesn't solve my problem does it?

It requires me to change brightness / contrast in a plugin (that will lower frame rate).

Then what is the benefit of the Neo here? Neos' output can't be played in 8.1.

8.1 gives a higher framrate on AVI's made with Vegas8 and doesn't mess with dynamics.

Since Neo won't play in 8.1 I'm sort of stuck between a slower 8.0c and Neo files or 8.1 and Vegas bigger AVIs. And sort of the same fps...


(Cineform Neo considerably better on a small laptop but most likely becasue it doesn't reauire so much hard disk activity. The big Vegas AVI files erquire good hd performance - which I have in my studio machine).

==============================

Glenn, what is the exact, step by step recipe for working with these 16-235 Neo files according to you? I have text, stills, graphics, 3D animations etc. all this material is 0-255 material. I have no lust for sitting readjusting all that... As output I need to render 0-255 material for computer screens. I also need to output material for 16-235 broadcast. Exactly what is the deal here with th CIneform Neo files. What are the easy adjustments you ar referring to and weher do I do them please...?

Best
Lars

It's laid out in my article.

In your case:
- Leave the Neo files alone.
- Convert all your computer RGB material to studio RGB by applying the levels FX to them.

When you render:
If it is to a codec that expects studio RGB, do nothing.
If it is to a codec that expects computer RGB, nest your project in a new one and add a studio -> computer RGB conversion to that. (Or render to an intermediate file, apply a levels FX to that, and render from that file.)

Hmmm... ;) May work... extra work... I'll call Cineform.

Of course it's extra work.
Having vision with illegal levels is the most common reason programs are reject by broadcasters and the most common cause of that are graphics and stills. Not only do you need to watch levels but also that your colors are not out of gamut if you want to know the whole horror story. Whenever you create media with Vegas watch for those yellow triangle warnings.

Bob.

It's laid out in my article.

Glen, I have the greatest respect for your knowledge about all things color management and correction. I am very appreciative of your willingness to share your knowledge and expertise with us mere mortals here in the Vegas community ;-}.

Also, as you may recall, I have your VASST Color Correction DVD. But I'll have to admit, when I read through the article (several times) my head was spinning. Not because you didn't do a good job - it is just complex stuff for folks like me.

That said, I'll try to suggest a few things that could possibly make it easier for me to understand:

1. First (and as an aside), it would really be helpful to me if the articles had a "published date" and "update history" so I could determine how current the information is.

2. I wish the article covered AVCHD.

3. I think a step-by-step color workflow along the lines of what you presented here in the remainder of your message I referenced (i.e., "In your case" and "When you render") is most helpful for me. It provides context for the reference material in your article. With that basic understanding, then the article becomes a useful reference that describes why these steps are as they are. I think a more complete collection of solid workflow examples would help me and possibly others get our heads wrapped around this.

4. I like using a table (as you did in your article) to organize complex information. For the workflows, it might be useful to have a table with a "source" axis, and a "target" axis. I think this is necessary for developing a full understanding because any one or more given sources (e.g., DV, HDV, AVCHD, JPEGs, generated media, etc.) might be targeted to one of any number of different targets. The intermediate steps required are determined by which source-target pair is selected, and a table can document this well.

At any rate, please don't take any of this as critical of your attempts to help us understand this stuff. I'm just trying to help confirm how wide the gap is between your knowledge and my understanding of all this.

Jerry

In my case I perceive the problem like there are two standards confronting each other 16--235 and 0-255.

I will spend some time and speak with broadcasters etc identify this - I simply need to create a step by stepdiagram that help me create a sensible work flow.

I spoke with some broadcast engineers yesterday (Europe): The 16-235 is corresponds to the range on the old analogue crt wave form monitors had, showing sync and the black to white portion. 16 there is the 0mV line and 235 is the 700 mV top line. Adding stuff above that 700mV line (235) will in 99% of the case have your material clipped by most broadcasters.

So, yes when delivering a video file or disc to a bradcast station it should conform to 16-235. ANd that would include and text generator components in the material of course.

When I do stuff intended for high quality viewing on computer screens, I do get more black blacks and a more punch if I stick to 0-255.

So my editing work has to fit several environments.

Working on a computer screen, looking at a Samsung monitor, where manus, and all other material is 0-255 it may make sense to work 0-255. No advantages 16-235 as i can see. Can you see any?

Is the 16-235 an issue for me as a creative video producer and editor? Or is it an issue for the broadcasters? Suerely them. And for me when delivering the project it needs to be 16-235.

But not necessarily whiole editing and åproduciong the material (?).

For fun I downloaded some 10 different podcasts from MSBNC. Vogue TV, etc etc. They are all 0-255. Most likely because they are intended to be viewed on PC screens... And what they broadcast is most likely 16-235.

Sitting and doing videos that are intended for web / computer and feeling proud for having *only* the 16-235 look (black is greyer and whites are a little dull - unless you change your monitor to re-compensate) and sending stuff to your client looking a little duller when they view in Windows Meida Player seems a bit pointless.

What am I gaining by limiting my dynamic range if I'm not broadcasting it? Nothing as far as I can see.

To me, right now, not knowing everything about this yet, and with the reservation to change my mind... to me it feels like 0-255 is the way to produce.

And then delivery is another story. A broadcaster in Europe, and another in the US etc may have specil requirements in regards to the dynamic range.

So what to do then? Identify what they want and make the settings on an output module plugin in Vegas to deliver exactly what the want.

Now a problem for me with Cineform. They do a GREAT job in transcoding the 5D2 footage into playable files. At the same time they convert from 0-255 to 16-235. Which they apparently do very well. But it means I will then have a mixture of source materials.

In the movie business and when watching files from RED cameras that are posted here and there, its a lot of 16-235 stuff.

And when viewing commercial well produced stuff intended for web viewing. It is mostly always 0-255.

My gut feeling, sitting in front of a PC is that I want everything to be 0-255. And then render to a large AVI-file the finished edited project to 0-255, to exactly what I see.

Then that is my master. That I can then render to be a 16-235 master for broadcast if that is reauired. Now compressing the dynamic range probably requires, just like everything else, skill and knowing exacly how to do this. It will involve actions that affect how you perceive color etc etc. So this needs to be identified and clarified.

I think Cineform and Sony should map out an easy to understand work flow here.

How you get the right dynamic range for the right client and how to alter the range without ruining the nice basic quality of your original footage.

I don't want to start a production/editing being stuck with 16-235 if I don't NEED that for the final product. And also, I need to know exactly what do do with a production that *IS* 0-255 and where there is a definite need to adapt to 16-235 broadcast regulations...

Please read this in the meantime from Cineforms blog...

- - - - - - - -

http://cineform.blogspot.com/

Quoting:

"Neo Scene has a 10-bit solution. Reducing the 8-bit data from 255 levels to only 220 levels (with 16-219) something will always be lost, so we bump the data to 10-bit first, a 0 to 1023 range, then reduce that data to the 10-bit YUV standard range of 64-940, which has the precision to maintain all the source levels without introducing image banding. It is this 10-bit range-corrected data that we compress to CineForm from the Canon 5D Mk-II. By normalizing the Canon 5D data, the full dynamic range is now preserved in all editing and viewing environments."

- - - - - - - -

While this is all well, how do I go about it if I indeed want info from 0-255 in my project from the 5D2 files? Expanding this 16-235 range from 16-235 in an 8-bit editing environment is perhaps not an ideal procedure? They transform the 8 bit original into 10 bit because its better to change levels in 10 compared to 8. So expanding while being in 8 isn't going to be ideal...

Now had there been a built in 16-235 < > 0-255 conversion utility in Vegas that did this in a proper way I guess it had been very useful.


Let's continue to disucss this and find clear and concise solutions and work flow examples! Example:

A) my footage is 5D2 converted by Cineform into an AVI file. Footage now is 16-235.

B) Other footage is animations coming in from another company 0-255 3D aninmations, logos etc.

C) Other sources are stills, produced in PhotoShop sRGB TIFs 0-255. 5616 pixel wide images.

D) Other sources are Vegas texts etc, that by dafault see white as 255.


Now I want to edit my program.
Then I want to plublish one 0-255 version for download on the web and viewing on PC monitors.
I then want to send it to a company for TV broadcast (then having the material for 16-235).

What settings in Vegas Pro 8 "display" do I want to use?
What setings in nVídia geForce to I want to use
My monitor is calibrated with Eye1 for 6500 K


How to create and define the best methof working here?



best,
Lars

Jerry, in the for-what-it's-worth department, I feel you pain!

Lars, excellent post. One thing I believe you are saying is if I am not submitting video for broadcast, I should always be working in 0-255. If that is true, that makes Cineform's approach very confusing for me. I was just getting ready to purchase Neo Scene for a large project that will be going on the Web and/or DVD or BD.

Have you tried converting the Neo Scene to 0-255? If so, how did it look?

Also, have you asked Cineform to explain why they don't give you the option of transcoding to 0-255? I would be interested in hearing why they don't.

Jerry

I really don't understand why people find this all so confusing but then again I'm an engineer and I couldn't write two lines of a script to save my life.

Of course anything destined for web delivery is going to be 0-255, if it didn't it would look a tad washed out. No surprises there.

Yes everything in the video world is 16-235, if it wasn't all manner of things would go wrong. Put 0-255 onto a DVD and it'll get clipped. From memory many NLE's and compositing programs might do the same thing. That means crushed blacks and clipped highlights.

You can argue all you like that video should be 0-255 but we're much too far down the track to change standards now and there was good reasons why that standard was settled on at the time. More to the point there's nothing worthwhile to be gain changing the standard. As Glenn has rightly pointed out the impact of multiple generations of running the transform is unnoticeable for all practical purposes.

I'd also point out that the eye is most sensitive to luma and the luma component of video is NOT 8 bit resolution, it's 8*8*8 bits. I'd also point out that many display devices are only 6 bits per channel and yet people watch them quite happily.

I'd also add that many video cameras record over 235. I wrangle this issue all the time and it's not that hard to get all my ducks in a line.

I'm also left wondering about the rest of the specs that this camera is recording to, levels are not the only issue to be considered if you want to really worry about the technical stuff. Not the least of them being to state it simple is this. 255,0,0 is red. Now which red is that meant to be exactly?

Bob.