Vegas Colorspace/Gamma Problem at DVinfo.net

Mo Zee · November 8th, 2008, 10:34 PM

I edit HD using PPro/Cineform, and I want to use Vegas to play back for screening purposes because I can get 5.1 discreet audio unlike in PPro. Also, for some reason, sync drifts in my setup in PPro with 6 audio tracks. I use an AJA Xena card to ouput video both in PPro and Vegas. Now when i import HD video in Vegas and play it back, it looks darker on the desktop display and much worse on my external monitor. I'm not sure if it's a colorspace or gamma problem. I exported 3 color bars from PPro: MSDV NTSC, Cineform 720p avi, H264 720p mov. The brightness bars go black except for the MSDV bars. This doesn't happen in PPro. Is there a workaround for this short of increasing the black level on my monitor?

Thanks

Edward Troxel · November 9th, 2008, 07:07 AM

You could add a color corrector and experiment with the "Studio RGB to Computer RGB" and "Computer RGB to Studio RGB settings". Those two presets are also in the "Levels" effect. I'm not sure which one would process faster.

Jeff Harper · November 9th, 2008, 07:54 AM

While my comment is likely of no help, I'd like to throw in that when I have played with PPro I was impressed with the quality of the preview screen, it appeared somewhat better than Vegas. At the time I thought it was my imagination, but possibly it is better and you are simply not used to the difference.

Bill Ravens · November 9th, 2008, 08:04 AM

Mo...

you've discovered the perennial problem Vegas has with color space. Depending on the codec, Vegas will do the conversion, on import, in different ways, depending on whether you select 8-bit or 32-bit processing in the project properties window. Vegas seems to have fundamental problems with Rec601/709 color mapping and/or YPbPr-RGB conversion. As Edward says, you can also use the LEVELS control to set conversion presets. I've found this method to be fairly unreliable. The best method I've found is to use the CURVES FX and adjust the endpoints of the curve, while watching the waveform monitor. Be aware that the WFM AND the preview window display can be incorrect. Which is why I've given up on Vegas.

Paul Kepen · November 9th, 2008, 03:34 PM

What version of Vegas did this color-space problem first pop up in?

I use to use V6, and did not notice near the problem I do with V8 in both dark output and color shift toward blue. The Computer to Studio RGB (or the other way around - I can't remember) corrects the darkness issue for the most part, although I think it over does it a bit for my taste, so I tweak it a bit. I also add some -blue +red to the enitre timeline. This more closely matches the same clips imported into Adobe PPro, without any adjustment. These clips when captured and played on the editing computer through PPro look exactly the same as the HDV tape when played with the Camcorder hooked directly to an HDTV monitor.

November 8th, 2008, 10:34 PM	#1
Mo Zee Regular Crew Join Date: Jan 2002 Location: manila, philippines Posts: 102	Vegas Colorspace/Gamma Problem I edit HD using PPro/Cineform, and I want to use Vegas to play back for screening purposes because I can get 5.1 discreet audio unlike in PPro. Also, for some reason, sync drifts in my setup in PPro with 6 audio tracks. I use an AJA Xena card to ouput video both in PPro and Vegas. Now when i import HD video in Vegas and play it back, it looks darker on the desktop display and much worse on my external monitor. I'm not sure if it's a colorspace or gamma problem. I exported 3 color bars from PPro: MSDV NTSC, Cineform 720p avi, H264 720p mov. The brightness bars go black except for the MSDV bars. This doesn't happen in PPro. Is there a workaround for this short of increasing the black level on my monitor? Thanks

November 9th, 2008, 07:07 AM	#2
Edward Troxel Sponsor: JET DV Join Date: Dec 2001 Location: Southern Illinois Posts: 7,953	You could add a color corrector and experiment with the "Studio RGB to Computer RGB" and "Computer RGB to Studio RGB settings". Those two presets are also in the "Levels" effect. I'm not sure which one would process faster. __________________ Edward Troxel [SCVU] JETDV Scripts/Scripting Tutorials/Excalibur/Montage Magic/Newsletters

November 9th, 2008, 07:54 AM	#3
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	While my comment is likely of no help, I'd like to throw in that when I have played with PPro I was impressed with the quality of the preview screen, it appeared somewhat better than Vegas. At the time I thought it was my imagination, but possibly it is better and you are simply not used to the difference.

November 9th, 2008, 08:04 AM	#4
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	Mo... you've discovered the perennial problem Vegas has with color space. Depending on the codec, Vegas will do the conversion, on import, in different ways, depending on whether you select 8-bit or 32-bit processing in the project properties window. Vegas seems to have fundamental problems with Rec601/709 color mapping and/or YPbPr-RGB conversion. As Edward says, you can also use the LEVELS control to set conversion presets. I've found this method to be fairly unreliable. The best method I've found is to use the CURVES FX and adjust the endpoints of the curve, while watching the waveform monitor. Be aware that the WFM AND the preview window display can be incorrect. Which is why I've given up on Vegas.

November 9th, 2008, 03:34 PM	#5
Paul Kepen Major Player Join Date: Dec 2004 Location: Minneapolis Minnesota Posts: 347	What version of Vegas did this color-space problem first pop up in? I use to use V6, and did not notice near the problem I do with V8 in both dark output and color shift toward blue. The Computer to Studio RGB (or the other way around - I can't remember) corrects the darkness issue for the most part, although I think it over does it a bit for my taste, so I tweak it a bit. I also add some -blue +red to the enitre timeline. This more closely matches the same clips imported into Adobe PPro, without any adjustment. These clips when captured and played on the editing computer through PPro look exactly the same as the HDV tape when played with the Camcorder hooked directly to an HDTV monitor.