Vegas - Did I color correct this correctly?

[sdsumike619]

The destination is DVD. I tried to calibrate both my computer monitor and external preview device (TV) as best I could. The video that was filmed was very washed out and I just want to make sure the blacks crisp and add some color to the skin. I've attached a screen shot showing the levels and color corrector, along with the waveform scope. Also showing the video scopes settings in case they are set incorrectly.
Thanks for any advice you may have!

color-correct-screen.png

[jagabo]

Looks a little over bright to me. Highlights are blown out -- though they are very small.

[edDV]

The only way to judge for sure is on a calibrated TV monitor. Id burn a test DVDR or use IEEE-1394 through an ADVC type box to the monitor for live timeline preview.

[poisondeathray]

Since your scope setup has studio rgb uncheckmarked, 0-100 IRE will correspond to 0-255 RGB or "computer levels" instead of 16-235 or "video levels". With your levels corrections I would expect on a DVD player blacks would crush and you'd lose detail, and whites would blow out...

But it's actually more complicated than that It also depends on what the source format is, what decoder vegas is using and if it expanded the luma range fully or not, and your project settings 8-bit vs. 32-bit, and the gamma settings (2.22 vs. linear), and the vegas version (vegas 9 treats things slightly differently than 8. )

But edDV is right. The only way to know for sure is the setup he described, or go through and burn a disc to watch.

http://www.glennchan.info/articles/vegas/v8color/vegas-9-levels.htm
http://www.sundancemediagroup.com/articles/glennchan/levels_in_sony_vegas_part_one.htm
http://www.sundancemediagroup.com/articles/glennchan/levels_in_sony_vegas_part_two.htm
https://forum.videohelp.com/topic346864.html

[sdsumike619]

ugggh.. Well the source is miniDV shot with an AG-DVC80 by Panasonic.
Don't know about the decoder?
Using Version 8.0c
and the other stuff I don't know either..

I know it will never be "perfect" because everyone has different settings on their TVs and computer monitors, but I would just like to try and be in the middle of the road so that on the average tv and/or monitor, they don't have to adjust bright/contrast extremely far to get a decent picture..

[poisondeathray]

But your target is a DVD. Not a PC or web based flash player. Remember that a PC display typically uses full range 0-255, and if you color correct using that, not a calibrated TV levels (16-235) monitor, you will get poor results.

You color corrected without studio RGB checkmarked in the scopes settings. (i.e. the scopes are calibrated to and expecting a 0-255 source)

If you checkmark the studio rgb box in the setup, you will notice that you will go well over 100 and well below 0. i.e. you will have blowouts, and crushed blacks once you burn to DVD

This is just my suspicion - there several other things that can affect the display, and the only way to know for sure is to burn a DVD and test.

[jagabo]

It doesn't matter that many peoples TVs will be out of adjustment -- that's their problem. Your job is to get the levels right so that you video is encoded properly. That way anyone with a properly adjusted TV will see the correct image. And anyone with an improperly adjusted TV will see your video looks just like all the other video they watch.

Levels are pretty easy to get right with a scope trace -- especially black levels. But, as poisondeathray pointed out, you must know your tools and exactly what they are showing you. Colors are more difficult unless you shot a color chart at the scene.

[sdsumike619]

poisondeathray, yes the target or end product IS a DVD, but DVDs can be watched on TVs and computers as you know. So it sounds like you're suggesting that the best practice would be to check the box for studio RGB and then adjust my levels according to that?

Is there a simple way to burn a test DVD? I use Adobe Encore to author and encode, but I don't want to encode 4 hours of video just to make a test disc to see how it looks. And if it's no good, then have to encode yet another 4 hours over again..

[jagabo]

Burn a few minutes of representative video to a DVD+RW.

[poisondeathray]

poisondeathray, yes the target or end product IS a DVD, but DVDs can be watched on TVs and computers as you know. So it sounds like you're suggesting that the best practice would be to check the box for studio RGB and then adjust my levels according to that?

This is exactly what I'm suggesting, and what my experience with vegas has suggested to me. But if you look at that info from Glenn Chan in those links above, it actually is a bit more complicated. The only way to be sure is to test the entire workflow out from input asset, to finished product viewed on your target device

It will look different when you watch that DVD on the PC vs. standalone DVD player hooked up to TV. , unless your PC software knows to scale the conversion to RGB for your PC display at 16-235, and your assets were legal range to begin with

I heard some newer model DVD players and TV's can accept non legal range video (i.e what I think you're currently making), but I don't have any experience with those setups

Is there a simple way to burn a test DVD? I use Adobe Encore to author and encode, but I don't want to encode 4 hours of video just to make a test disc to see how it looks. And if it's no good, then have to encode yet another 4 hours over again..

Jagabo answered that one very appropriately. RW's are great for testing workflow.

If your assets are already encoded, you don't have to re-encode. You don't even have to author the entire disk with menus etc... Just a mini-test. You're specifically testing to see the levels and if whites are blown out, and the black level is correct etc...on an appropriate section that will be able to show these areas.

[edDV]

A hardware DVD player will D/A digital level 16 to 7.5 IRE (NTSC) or 0.0 IRE (PAL) and 235 white to 100 IRE (NTSC and PAL).

A software DVD player (e.g. MP, Power DVD, etc.) will scale 16-235 properly for the computer.

[sdsumike619]

So if I'm reading this correctly, there is no "correct" if the DVD is to be played on both computers and tabletop players since levels are treated differently?

In order for me to create a test DVD, then I should just encode a short section of one of my time lines to NTSC avi from Vegas, the import into an Adobe Encore project and perhaps use that asset as a first play and not bother with any menu? Because I use Adobe's MPEG encoder so I imagine that yet something else will happen to the levels during the MPEG-2 encoding as well...

There's too many variables that come into play with these levels to even try to figure any of it out. It seems like once I think I understand it, there's another "if"

[edDV]

So if I'm reading this correctly, there is no "correct" if the DVD is to be played on both computers and tabletop players since levels are treated differently?

Absolutely not. DVD is always 16 for black and 235 for white. It is the job of the player to scale 16-235 to the players output format be it NTSC, PAL, analog components, DVI, HDMI. In the case of a computer software player, the player-display card scale 16-235 YCbCr to 0-255 RGB for computer monitor display.
All of these digital video standards use 16-235:

DV, DVCAM, DVC-Pro, DigiBeta, HDCAM
MPeg2, DVD, HDV, XDCAM, ATSC, DVB,
MPeg4, h.264, AVCHD, VC-1
etc.

This should make it easy for an NLE. No matter what the import/export format, a 16-235 timeline imports and exports YCbCr with no levels change. RGB 0-255 format needs conversion. So for monitoring, it is better to directly monitor the YCbCr timeline rather than convert to RGB for computer display. Vegas Pro includes an LCD monitor calibration procedure* but this is intended for broadcast monitors that properly spec color and gamma. Consumer computer monitors and LCD-TV sets are difficult to calibrate.


If you can't do that, then you need to burn a test DVD and use your DVD player to feed the monitor.

See Vegas Help "External Monitor via IEEE-1394" and "Previewing Video on a Secondary Windows Display".

[edDV]

The most basic calibration starts with the SMPTE color bar or better the BelleNuit levels chart. Burn this* to the test DVDR
and calibrate the monitor to the chart. The THX optimizer can also be used. They should get similar results.


http://www.belle-nuit.com/testchart.html

Ever wonder how a TV network can run 50 clips from 50 sources back to back in a commercial break and have consistent levels? It is because each of those 50 production companies calibrated their production system to a common standard represented by that chart.


* better to encode the chart to a few minutes of MPEG2 to test the timeline and encoder path.

[jagabo]

This post links to a DVD ISO image and a VOB file that contain the Macbeth color chart:

https://forum.videohelp.com/topic370409.html#1986266

[edDV]

In order for me to create a test DVD, then I should just encode a short section of one of my time lines to NTSC avi from Vegas, the import into an Adobe Encore project and perhaps use that asset as a first play and not bother with any menu? Because I use Adobe's MPEG encoder so I imagine that yet something else will happen to the levels during the MPEG-2 encoding as well...

There's too many variables that come into play with these levels to even try to figure any of it out. It seems like once I think I understand it, there's another "if"

If you are encoding before use of Encore and just importing pre-encoded assets into Encore, then use of Encore is optional. You are testing the encoded files. If you are encoding from within Encore, then you need to test the full process.

Here is how I'd do a test DVD.

First you need a header the to calibrate the DVD player and monitor.

1. 2 min SMPTE color bar for rough levels setup.

DVD players vary for out of box calibration. First adjust the tv for acceptable levels on your best TV channel. Switch to the DVD player and run the color bar and/or go through the THX Optimizer (without changing TV settings) to see how close your player matches the TV tuner. If it is way out on black level or contrast, adjust the DVD player from the setup menu (brightness, contrast) for a close match. Then run though the THX optimizer making fine adjustments to the TV or adjust to the color bar.

2. 2 min BellNuit color bar for fine levels setup.

Play the BelleNuit color bar and fine adjust black level. Levels 0-16 should all appear full black but level 20 should show brighter than black. Adjust TV "brightness" control.

Observe levels 235-255. 255 should represent the brightest your TV can produce without clipping. Levels 231 to 255 should show distinct levels. Adjust TV "contrast" control.

The black to white linearity steps should be evenly stepped and the linearity sweep should be centered horizontally. If not, adjust TV "gamma".

Next set chroma saturation and hue for proper colors.

The corner arrows will show if your picture is centered.

The fine setup should be confirmed before any color correction tests are performed.

3. Run your sample clips without correction then with correction. Put a chapter index at the start of each clip so you can replay easily or run clips as separate files.

[poisondeathray]

In the screenshot above, I bet edDV has his scopes set 16-235 "studio rgb" checkmarked, because you can see ~110 to ~-10 IRE on the waveform monitor with the belle nuit test chart. So the legal range of 16-235 from the test chart are mapped to 0-100 IRE on the waveform monitor. The ranges 0-16 and 235-255 from the test chart, are indicated by below 0 IRE and above 100 IRE on the waveform monitor are "not legal".

If edDV had it uncheckmarked , like you did in the 1st post, it would read 0-100 correlating to the 0 and 255 patches on the test chart. So if you did your levels corrections using this setting, it would include those "illegal" ranges.

[edDV]

In the screenshot above, I bet edDV has his scopes set 16-235 "studio rgb" checkmarked, because you can see ~110 to ~-10 IRE on the waveform monitor with the belle nuit test chart. So the legal range of 16-235 from the test chart are mapped to 0-100 IRE on the waveform monitor. The ranges 0-16 and 235-255 from the test chart, are indicated by below 0 IRE and above 100 IRE on the waveform monitor are "not legal".

If edDV had it uncheckmarked , like you did in the 1st post, it would read 0-100 correlating to the 0 and 255 patches on the test chart. So if you did your levels corrections using this setting, it would include those "illegal" ranges.

Yes it is set to "Studio RGB 16-235"

The 0-15 and 236-255 buffer regions were added to ITU-Rec-601 digital video to prevent hard white and black clipping that occurs when 0-255 is used. This gives approximate a 7% overshoot range for improper signal levels before clipping occurs. That means equipment level errors in a transmission system can be corrected at the destination. Hard clipping is a no no for D/A because it causes alias products in the analog conversion.

At the black end of the scale, a monitor should be adjusted for black at level 16. Any video that exists below 16 will show as black (aka black crush). If during recording, an error caused black to be recorded below 16, it can be corrected with color correction (luminance adjustment). Any signal below 16 will be visible on a waveform monitor but not on a properly adjusted video display.

At the white end of the scale, nominal white exists at level 235 but the system allows highlight overshoots into the 236-255 region. Think bright clouds or studio lights getting into the shot. A properly adjusted display should be able to display level 255 overshoots without clipping or blooming (CRT). The amount of total energy allowed in the 236-255 region should be moderated to prevent serious problems post D/A (e.g. CRT bloom, analog transmitter overload or analog VCR over-modulation). The 236-255 overshoot region allows over hot whites to be toned down during color correction without distortion.

For analog NTSC and PAL broadcast, it was common to have whites overshoot as much as 20% or 120 IRE. This was built into the NTSC and PAL specs. When digital specs were created in the 80's, camera stability had improved to the point it was decided to limit overshoots to about 108 IRE thus favoring signal to noise.

For "color correction", source can have up to 7% errors on black or white levels and still be correctable. As for output, DVD, Blu-Ray, ATSC and DVB all can pass the 0-16 and 236-255 overshoot regions but in practice sub 16 is not passed and 236-255 is reserved for details like clouds or super-white effects (e.g. explosions). Cable and satellite have compromised the standard by requiring white clamps (not clips) at 235 to improve signal to noise. I see that they still permit some sub 16 to allow for black correction without crush. Therefore, anything captured from cable or sat is likely to be constrained to near 16-235 but DTV, DVD or Blu-Ray may use some of the 236-255 region.

The above applies to pro video. When you consider consumer camcorders, all rules are broken. Consumer camcorders routinely break the rules by pushing peak whites to 108 IRE or higher (clipping) in order to exaggerate signal to noise specs and to "fake" low light performance. This has been true for most consumer VHS-C, Video8, Hi8, Digital8 and MiniDV camcorders and continues with consumer HDV and AVCHD models. So in effect, the 236-255 headroom is ignored and they (digital formats) instead record 16-255 with substantial clipping at 255. Thus, when considering consumer camcorder source, one should expect to moderate whites down from 255 to 235 to prevent overly bright monitor display compared to broadcast or DVD source. At the next level, you need to deal with "blown out" or clipped whites such as loss of cloud detail.