Rec 709 16-235 in Video Pro X6

discburn wrote on 5/8/2014, 3:16 AM

Just wondering how to use the Measuring Instruments in VPX6 for Broadcast 
range of 16 - 235?

I understand that Rec 709 is 0-255 for Web, and perhaps for DVD, Blu-ray, 
etc. But I've read that Rec 709 must be set to 16-255 for Broadcast. Some 
editors even consider it safest to set Rec 709 to 16-255 for DVDs, Blu-ray, 
Web, etc.

In the Measuring Instruments the range seems to go (basically) from 0 at the 
bottom to 255 at the top. Auto Correction for Exposure and Colour moves the 
Waveform Monitor content, for example, down to 0 and up to 255.

But where is the range for 16-235? I see in the Help Dialogue about the 
Waveform Monitor, it says...
'The dotted lines on the upper and lower borders of the waveform monitor 
correspond to the values for digital 0 (black) and digital 255 (white).
The lines 0 and 100 on the left border correspond to the limit values for 
analog transfer of video signals.'
Does the last sentence (The lines 0 and 100 on the left border, etc.) refer 
to Rec 709 16-235? If yes, I find it's easy to bring the white down to the 
100 line, but very difficult to bring the black up to the 0.

Anybody any advice on the above?

Seamus

Comments

johnebaker wrote on 5/9/2014, 2:57 PM

Hi

The information you are looking for re REC 709 ( BT 709 is the correct name ) is in the pdf manual p177 onwards under Histogram.  There is a preset for fro BT 709.

What this preset does is set the maximum black levels to 16 and the maximum white levels to 235. 

In other words a lowering of the contrast of the resulting video.

John

 

Last changed by johnebaker on 5/9/2014, 2:59 PM, changed a total of 2 times.

VPX 16, Movie Studio 2025, and earlier versions 2015 and 2016, Music Maker Premium 2024.

PC - running Windows 11 23H2 Professional on Intel i7-8700K 3.2 GHz, 16GB RAM, RTX 2060 6GB 192-bit GDDR6, 1 x 1Tb Sabrent NVME SSD (OS and programs), 2 x 4TB (Data) internal HDD + 1TB internal SSD (Work disc), + 6 ext backup HDDs.

Laptop - Lenovo Legion 5i Phantom - running Windows 11 23H2 on Intel Core i7-10750H, 16GB DDR4-SDRAM, 512GB SSD, 43.9 cm screen Full HD 1920 x 1080, Intel UHD 630 iGPU and NVIDIA GeForce RTX 2060 (6GB GDDR6)

Sony FDR-AX53e Video camera, DJI Osmo Action 3 and Sony HDR-AS30V Sports cams.

discburn wrote on 5/9/2014, 3:23 PM

Thanks John,

I'm actually working with the Waveform Monitor, too.  I see that has two settings:

1.  Dotted Lines 0 at bottom and 255 at top.

2.  Hard Lines 0 - 100 between the dotted lines.

My understanding is that black level 16 is the Hard Line 0 and white level 235 is the hard line 100.

So I'm trying to keep my signal between the 0 - 100, only allowing transients to go below or above.

Interestingly, though, if I import footage into VPX6, while the preset is set to BT 709, blacks can go right down to dotted line 0 and up to dotted line 255.

Also, Auto Exposure and Auto Color distribute the signal right down to 0 and up to 255.

So I'm not sure how the preset works at setting maximum levels at 16 - 235.  Maybe I'm misunderstanding the levels as laid out in the Waveform Monitor?

Appreciate more input on this, thanks.

Seamus

 

Last changed by discburn on 5/9/2014, 3:23 PM, changed a total of 1 times.

Samplitude Pro X3, Video Pro X6, Dell Precision T5500,  Windows 7 Professional, 64 bit, SP 1,  Intel Xeon X5650 @ 2.67GHz and 2.66HGHz (2 processors),  48 GB,  M-Audio Delta 1010LT,  NVIDIA Quadro 4000

johnebaker wrote on 5/9/2014, 6:33 PM

Hi

Post removed - see above correction

John

 

 

Last changed by johnebaker on 5/10/2014, 4:01 PM, changed a total of 2 times.

VPX 16, Movie Studio 2025, and earlier versions 2015 and 2016, Music Maker Premium 2024.

PC - running Windows 11 23H2 Professional on Intel i7-8700K 3.2 GHz, 16GB RAM, RTX 2060 6GB 192-bit GDDR6, 1 x 1Tb Sabrent NVME SSD (OS and programs), 2 x 4TB (Data) internal HDD + 1TB internal SSD (Work disc), + 6 ext backup HDDs.

Laptop - Lenovo Legion 5i Phantom - running Windows 11 23H2 on Intel Core i7-10750H, 16GB DDR4-SDRAM, 512GB SSD, 43.9 cm screen Full HD 1920 x 1080, Intel UHD 630 iGPU and NVIDIA GeForce RTX 2060 (6GB GDDR6)

Sony FDR-AX53e Video camera, DJI Osmo Action 3 and Sony HDR-AS30V Sports cams.

discburn wrote on 5/10/2014, 12:02 AM

Hi John,

I seem to be misunderstanding the measuring instruments.  I didn't realise the Histogram BT 709 was a video effect as such, but just a measuring device.  Thanks for your patience.  Do you know if there is any kind of step by step tutorial for using the instruments?  I'm accustomed to Media Composer where you actually set the 16-235 levels manually in the measuring instruments section.

Seamus

Last changed by discburn on 5/10/2014, 12:02 AM, changed a total of 1 times.

Samplitude Pro X3, Video Pro X6, Dell Precision T5500,  Windows 7 Professional, 64 bit, SP 1,  Intel Xeon X5650 @ 2.67GHz and 2.66HGHz (2 processors),  48 GB,  M-Audio Delta 1010LT,  NVIDIA Quadro 4000

johnebaker wrote on 5/10/2014, 4:00 PM

Hi

. . . . I seem to be misunderstanding the measuring instruments. . . . .

Apologies you are not the only one    my previous post was in error in assuming the Histogram BT 709 was an actual adjustment when in fact it is setting the limits of the instruments such that they indicate when the limits of the specification are exceeded.

There are tutorials - mainly for Premiere - but the principles are the same - about using some of these instruments on Youtube.

John

Last changed by johnebaker on 5/10/2014, 4:47 PM, changed a total of 3 times.

VPX 16, Movie Studio 2025, and earlier versions 2015 and 2016, Music Maker Premium 2024.

PC - running Windows 11 23H2 Professional on Intel i7-8700K 3.2 GHz, 16GB RAM, RTX 2060 6GB 192-bit GDDR6, 1 x 1Tb Sabrent NVME SSD (OS and programs), 2 x 4TB (Data) internal HDD + 1TB internal SSD (Work disc), + 6 ext backup HDDs.

Laptop - Lenovo Legion 5i Phantom - running Windows 11 23H2 on Intel Core i7-10750H, 16GB DDR4-SDRAM, 512GB SSD, 43.9 cm screen Full HD 1920 x 1080, Intel UHD 630 iGPU and NVIDIA GeForce RTX 2060 (6GB GDDR6)

Sony FDR-AX53e Video camera, DJI Osmo Action 3 and Sony HDR-AS30V Sports cams.

johnebaker wrote on 5/10/2014, 4:45 PM

Hi

. . . . I find it's easy to bring the white down to the 100 line, but very difficult to bring the black up to the 0. . . . .

At last I am beginning to get my head round this!

Are you using the Brightness adjustment to bring the white level down - if so then the Contrast is used to adjust the Black level up / down.

John

Last changed by johnebaker on 5/10/2014, 4:45 PM, changed a total of 1 times.

VPX 16, Movie Studio 2025, and earlier versions 2015 and 2016, Music Maker Premium 2024.

PC - running Windows 11 23H2 Professional on Intel i7-8700K 3.2 GHz, 16GB RAM, RTX 2060 6GB 192-bit GDDR6, 1 x 1Tb Sabrent NVME SSD (OS and programs), 2 x 4TB (Data) internal HDD + 1TB internal SSD (Work disc), + 6 ext backup HDDs.

Laptop - Lenovo Legion 5i Phantom - running Windows 11 23H2 on Intel Core i7-10750H, 16GB DDR4-SDRAM, 512GB SSD, 43.9 cm screen Full HD 1920 x 1080, Intel UHD 630 iGPU and NVIDIA GeForce RTX 2060 (6GB GDDR6)

Sony FDR-AX53e Video camera, DJI Osmo Action 3 and Sony HDR-AS30V Sports cams.

Scenestealer wrote on 5/10/2014, 6:01 PM

Hi John

That sounds back to front. Normally the brightness controls the black level and Contrast the white level.

Selective Brightness (in MEP) is the Gamma adjustment.

Peter

Last changed by Scenestealer on 5/11/2014, 11:04 PM, changed a total of 2 times.

Reason: wrong word - brightness instead of contrast

System Specs: Intel 6th Gen i7 6700K 4Ghz O.C.4.6GHz, Asus Z170 Pro Gaming MoBo, 16GB DDR4 2133Mhz RAM, Samsung 850 EVO 512GB SSD system disc WD Black 4TB HDD Video Storage, Nvidia GTX1060 OC 6GB, Win10 Pro 2004, MEP2016, 2022 (V21.0.1.92) Premium and prior, VPX7, VPX12 (V18.0.1.85). Microsoft Surface Pro3 i5 4300U 1.9GHz Max 2.6Ghz, HDGraphics 4400, 4GB Ram 128GB SSD + 64GB Strontium Micro SD card, Win 10Pro 2004, MEP2015 Premium.

discburn wrote on 5/12/2014, 1:48 AM

There seem to be some problems within VPX6 and its Measuring Instruments that are hard to define.  As though it is reading / displaying the 0-255 and 16-235 colour space flags incorrectly.

1.  It imports DSLR footage incorrectly - the blacks are crushed.  'Dark' footage has to be transcoded to another format before import.

2.  After import of any footage, the blackest signal is placed at the 0 line on the 0 - 255 scale (Waveform Monitor and Histogram).  In Media Composer, another NLE I use, it's placed at the 16 line of its 0 - 255 scale.

3.  In MPEG Streamclip I transcoded DSLR footage (with plenty of blacks) to DNxHD at 0-255 AND 16-235.  When imported to VPX6, both clips are place at the upper 0 line (IRE 0, I believe, the one above the bottom 0 in the Waveform Monitor), and the blacks have become a washed-out gray!  In Media Composer, both clips are placed at the 16 line and look great.

4.  Media Composer handles 'Broadcast Colour Space' logically and correctly.  It's Waveform scale, from bottom up, is 0, 16, 235, 255.  16 - 235 is for Broadcast.  In VPX6, the Waveform scale is 0, 0, 100, 255.  I suppose the middle 0 - 100 is Broadcast limits, but it seems impossible to get black at the Broadcast limit of 0.  It's a gray!

In VPX6 the Brightness and Contrast sliders seem inter-dependent.  I've found increasing the Brightness level lifts the blacks up from the bottom immediately (controls black level).  Decreasing it, brings the whites down.  The Contrast adjusts the blacks at the bottom end.

FINALLY, I love VPX6's 64-bit speed.  For now, I'm going to completely ignore what the measuring instruments say.  Just colour correct and get a good picture on a calibrated monitor.  I've exported HD files and burned Blu-rays and they all look great on various screens.

I still don't really know where or what the Broadcast levels are in VPX6, and my material is not for broadcast at this point, so, until this issue is resolved, I'll just keep editing.

Any further insights welcome!

Seamus

Last changed by discburn on 5/12/2014, 1:48 AM, changed a total of 1 times.

Samplitude Pro X3, Video Pro X6, Dell Precision T5500,  Windows 7 Professional, 64 bit, SP 1,  Intel Xeon X5650 @ 2.67GHz and 2.66HGHz (2 processors),  48 GB,  M-Audio Delta 1010LT,  NVIDIA Quadro 4000

johnebaker wrote on 5/12/2014, 3:17 PM

Hi

. . . . That sounds back to front. Normally the brightness controls the black level and Contrast the white level. . . . .

That sounds back to front to me   - brightness by definition is 'the intensity of the energy output of a visible light source'  and contrast the ratio between the darkest and lightest points

That is:

    - as you increase the brightness, the source emits more light and if taken to the maximum on a monitor gives white.

    - as you increase Contrast the bigger the difference between the black and white and vice versa.

@ Discburn - . . . . Just colour correct and get a good picture on a calibrated monitor. . . .

I agree totally with this method especially after burning BD with the video set to comply with BT 709 and doing it by eye.  The BT709 disc lacked contrast and punch on bright colours and generally look as if some shots, taken on bright days, were actually taken on dull overcast days.

John

 

Last changed by johnebaker on 5/12/2014, 3:17 PM, changed a total of 1 times.

VPX 16, Movie Studio 2025, and earlier versions 2015 and 2016, Music Maker Premium 2024.

PC - running Windows 11 23H2 Professional on Intel i7-8700K 3.2 GHz, 16GB RAM, RTX 2060 6GB 192-bit GDDR6, 1 x 1Tb Sabrent NVME SSD (OS and programs), 2 x 4TB (Data) internal HDD + 1TB internal SSD (Work disc), + 6 ext backup HDDs.

Laptop - Lenovo Legion 5i Phantom - running Windows 11 23H2 on Intel Core i7-10750H, 16GB DDR4-SDRAM, 512GB SSD, 43.9 cm screen Full HD 1920 x 1080, Intel UHD 630 iGPU and NVIDIA GeForce RTX 2060 (6GB GDDR6)

Sony FDR-AX53e Video camera, DJI Osmo Action 3 and Sony HDR-AS30V Sports cams.

discburn wrote on 5/12/2014, 3:37 PM

I've emailed a list of 'bugs' to Magix support.  I received a reply stating that the Measuring Instruments, as they are only new, are not yet connecting well with other elements of the software.

This 64-bit version is really fantastic.  Just needs a good polishing!

I hope a patch / update comes out soon!

Seamus

Last changed by discburn on 5/12/2014, 3:37 PM, changed a total of 1 times.

Samplitude Pro X3, Video Pro X6, Dell Precision T5500,  Windows 7 Professional, 64 bit, SP 1,  Intel Xeon X5650 @ 2.67GHz and 2.66HGHz (2 processors),  48 GB,  M-Audio Delta 1010LT,  NVIDIA Quadro 4000

Scenestealer wrote on 5/13/2014, 7:17 AM

Hi John

Fair enough but I think you know what I mean.  The problem with using the brightness to adjust the white is that it requires so much movement of the control to change the white noticeably that the black is thrown way off and of course the two (Br and Con) are inter related. Some useful stuff here: http://spareroommedia.com/video/monitor_setup.html

Seamus

Try loading one of the SMPTE Colour bar charts that are in the Test Images folder in Magix onto the timeline and see where the PLUGE strips (bottom second from the right) and the 100/100  bars, fall on the Scope. Only have MEP here but if I apply the Auto Exposure setting it does not change the exposure, black or white, sort of confirming what you said that they put it at maximum black and 255 white. 

Peter 

Last changed by Scenestealer on 5/13/2014, 7:17 AM, changed a total of 1 times.

System Specs: Intel 6th Gen i7 6700K 4Ghz O.C.4.6GHz, Asus Z170 Pro Gaming MoBo, 16GB DDR4 2133Mhz RAM, Samsung 850 EVO 512GB SSD system disc WD Black 4TB HDD Video Storage, Nvidia GTX1060 OC 6GB, Win10 Pro 2004, MEP2016, 2022 (V21.0.1.92) Premium and prior, VPX7, VPX12 (V18.0.1.85). Microsoft Surface Pro3 i5 4300U 1.9GHz Max 2.6Ghz, HDGraphics 4400, 4GB Ram 128GB SSD + 64GB Strontium Micro SD card, Win 10Pro 2004, MEP2015 Premium.

discburn wrote on 5/13/2014, 8:48 AM

Peter,

That's exactly right.  SMPTE Bars come in at 0 - 255.

The same bars imported to Media Composer come in at 16 - 235.

Seamus

Last changed by discburn on 5/13/2014, 8:48 AM, changed a total of 1 times.

Samplitude Pro X3, Video Pro X6, Dell Precision T5500,  Windows 7 Professional, 64 bit, SP 1,  Intel Xeon X5650 @ 2.67GHz and 2.66HGHz (2 processors),  48 GB,  M-Audio Delta 1010LT,  NVIDIA Quadro 4000

Scenestealer wrote on 5/13/2014, 4:18 PM

Hi Seamus

And I read somewhere that Premiere and After Effects read differently also...!

Peter

Last changed by Scenestealer on 5/13/2014, 4:18 PM, changed a total of 1 times.

System Specs: Intel 6th Gen i7 6700K 4Ghz O.C.4.6GHz, Asus Z170 Pro Gaming MoBo, 16GB DDR4 2133Mhz RAM, Samsung 850 EVO 512GB SSD system disc WD Black 4TB HDD Video Storage, Nvidia GTX1060 OC 6GB, Win10 Pro 2004, MEP2016, 2022 (V21.0.1.92) Premium and prior, VPX7, VPX12 (V18.0.1.85). Microsoft Surface Pro3 i5 4300U 1.9GHz Max 2.6Ghz, HDGraphics 4400, 4GB Ram 128GB SSD + 64GB Strontium Micro SD card, Win 10Pro 2004, MEP2015 Premium.

discburn wrote on 5/14/2014, 3:48 AM

Hi Peter,

I'm planning to invest in a 'cheap' reference monitor connected via Blackmagic Decklink Mini Monitor's SDI.  Hopefully that'll sort out a few things, and not create further confusion!

Seamus

Last changed by discburn on 5/14/2014, 3:48 AM, changed a total of 1 times.

Samplitude Pro X3, Video Pro X6, Dell Precision T5500,  Windows 7 Professional, 64 bit, SP 1,  Intel Xeon X5650 @ 2.67GHz and 2.66HGHz (2 processors),  48 GB,  M-Audio Delta 1010LT,  NVIDIA Quadro 4000