Rec 709 and Rec 709 16-235

[Alex De Vivo]

Wich setting should I use? And why? Thanks!

 

[Alex De Vivo]

Anybody there?

 

[Noah Kadner]

Use for anything in particular?

 

[Alex De Vivo]

I'm doing some color grading with After Effects CS4. I've edited with Avid Media Composer converting the R3D files into a .mov with a DNxHD codec (I converted the files with RedCine). I know that I should use a Rec 709 workflow, but I don't know if I should use a Rec 709 or Rec 709 (16-235). When I use Rec 709 (16-235) the image looks darker.

 

[Patrick Tresch]

16-235 as opposed to 0-255 is just the way luminance and chroma are mapped in 8 bit level (256 levels or steps).

If you plan to do a video output (YUV) with a graphic card that has broadcast signal output, you should use 16-235. (16 is black and 235 is the clipping point of white, under and over these limits you get an illegal broadcast signal)
If you plan to work further in a RGB space like for the WEB, computer monitoring or another graphic application like Photoshop... you should stay in 0-255 mapping.

Hope I was clear....

Patrick

 

[Alex De Vivo]

The final output will be a video for the HDTV, full hd. So, should I use the 16-235?

 

[Nir Shelter]

Yes for grading your footage, that way you'll be very close to your legal levels and colors and little will change when put to broadcast. By change I mean details in your lights and shadows.

 

[Alex De Vivo]

What happens if I use the Rec 709 0-255?

 

[Alex De Vivo]

16-235 as opposed to 0-255 is just the way luminance and chroma are mapped in 8 bit level (256 levels or steps).

If you plan to do a video output (YUV) with a graphic card that has broadcast signal output, you should use 16-235. (16 is black and 235 is the clipping point of white, under and over these limits you get an illegal broadcast signal)
If you plan to work further in a RGB space like for the WEB, computer monitoring or another graphic application like Photoshop... you should stay in 0-255 mapping.

Hope I was clear....

Patrick

Hi Patrick,

yes, you was clear... only another question: as I told the final output will be HDTV. This video (a short) is for HDTV (HD Ready and Full Hd).

When I say that the final ouput will be HDTV I mean that I'm going to do a blue ray (and even a DVD) for HD screens.

The question is: what do you mean when you say "graphic card that has broadcast signal output"?. My graphic card at the moment is a simple Radeon HD4870.

 

[Peter Hebert]

Hi Patrick,

The question is: what do you mean when you say "graphic card that has broadcast signal output"?. My graphic card at the moment is a simple Radeon HD4870.

I think he is referring to a something like the Blackmagic Decklink or the Matrox MXO that has a broadcast SDI / HD-SDI output, that can be connected to professional decks and monitors for recodring/monitoring.

 

[Alex De Vivo]

I think he is referring to a something like the Blackmagic Decklink or the Matrox MXO that has a broadcast SDI / HD-SDI output, that can be connected to professional decks and monitors for recodring/monitoring.

Uhm... unfortunately I'm not using Blackmagic Decklink or Matrox MXO... my pc in connected to an LCD via HDMI.

 

[Patrick Tresch]

Uhm... unfortunately I'm not using Blackmagic Decklink or Matrox MXO... my pc in connected to an LCD via HDMI.

If your use is DVD or Blueray you don't have to be in a legal broadcast signal as the compression application that will make your MPG2 file can handle RGB values (0-255).

Patrick

 

[Alex De Vivo]

Ok, so I can use a Rec 709 0-255 without problems?

 

[Patrick Tresch]

Ok, so I can use a Rec 709 0-255 without problems?

Yes, you could... test it...:emote_headwall:

REC 709 has 16-235 coding.

Pat

 

[Alex De Vivo]

Uhm ok, maybe there's a litlle misunderstanding:

In Adobe After Effects I can choose 2 settings: Rec 709 and Rec 709 (16-235). The first one I think is 0-255, the second one is obviously 16-235.

As I told I will create a Blueray and a DVD.

Now, what should I do?

 

[Maz Mawlawi]

if you are not broadcasting just use 0-255 for your Blueray

 

[MichaelP]

if you are not broadcasting just use 0-255 for your Blueray

The issue with this are the DVD players that have a "cinema" mode which basocally takes the 16-235 and makes it 0-255. If you have 0-255 to start, it can crush the blacks.

Michael

 

[Alex De Vivo]

The issue with this are the DVD players that have a "cinema" mode which basocally takes the 16-235 and makes it 0-255. If you have 0-255 to start, it can crush the blacks.

Michael

What would you do?

 

[Maz Mawlawi]

there is really no solution that will work fro every environment...you can use 16-235 and lose some of the contrast on some players...or use 0-255 and run the risk of crushing the contrast too much on other players...I personally use 0-255 for Blue ray....

 

[Job ter Burg]

I stick to 16-235.

If you encode 0-255, and play back on a properly calibrated setup, the display will lose any detail below 16 and over 235.