Milky blacks on DVD at DVinfo.net

Morten Gjerstad · August 27th, 2007, 06:41 AM

I've noticed that when I play my DVD's in Windows Media Player the blacks look more milky/gray and there is more compression noise than when I play them in VLC Media Player. I've also noticed this difference on various standalone DVD players. Does anyone have an explenation on why this happens?

Eric Darling · August 27th, 2007, 09:42 AM

Perhaps it has to do with pedestal/black level settings? DVD players and software often have menu settings where you can select to add or reduce pedestal to the video signal. I know that Windows Media Player has a Black Level adjustment.

David Tamés · August 28th, 2007, 03:32 PM

It does in fact have to do with the 7.5 IRE set-up (pedestal). The "standard" for digital video is blacks are at 0 IRE. But the "standard" for analog video is black at 7.5 IRE. So by default, according to the "standard" DVD players ADD 7.5 set-up to the video on the analog outputs. When you edit digital video, you need to make sure your blacks are all at 0, not 7.5, so when the DVD player adds the "standard" 7.5 set-up, your blacks only get slightly milky, rather than really milky. Some DVD players will allow you to change this setting, most do not. This is all a hold-over from ancient times when analog TV sets had trouble telling the difference between 0 and negative synchronization signals so the engineers decided to make black 7.5 rather than 0 for broadcast. How nice. There goes solid blacks. Not a problem in the era of CRT screens (grey surface to start with), but on LCD monitors, plasma displays, and projectors, the 7.5 is visible as non-black.

August 27th, 2007, 06:41 AM	#1
Morten Gjerstad Regular Crew Join Date: Nov 2005 Posts: 29	Milky blacks on DVD I've noticed that when I play my DVD's in Windows Media Player the blacks look more milky/gray and there is more compression noise than when I play them in VLC Media Player. I've also noticed this difference on various standalone DVD players. Does anyone have an explenation on why this happens?

August 28th, 2007, 03:32 PM	#3
David Tamés Kino-Eye Join Date: Jul 2005 Location: Boston, MA Posts: 457	It does in fact have to do with the 7.5 IRE set-up (pedestal). The "standard" for digital video is blacks are at 0 IRE. But the "standard" for analog video is black at 7.5 IRE. So by default, according to the "standard" DVD players ADD 7.5 set-up to the video on the analog outputs. When you edit digital video, you need to make sure your blacks are all at 0, not 7.5, so when the DVD player adds the "standard" 7.5 set-up, your blacks only get slightly milky, rather than really milky. Some DVD players will allow you to change this setting, most do not. This is all a hold-over from ancient times when analog TV sets had trouble telling the difference between 0 and negative synchronization signals so the engineers decided to make black 7.5 rather than 0 for broadcast. How nice. There goes solid blacks. Not a problem in the era of CRT screens (grey surface to start with), but on LCD monitors, plasma displays, and projectors, the 7.5 is visible as non-black. __________________ David Tames { blog: http://Kino-Eye.com twitter: @cinemakinoeye }

August 27th, 2007, 09:42 AM	#2
Eric Darling Major Player Join Date: Jun 2006 Location: Savannah, GA Posts: 463	Perhaps it has to do with pedestal/black level settings? DVD players and software often have menu settings where you can select to add or reduce pedestal to the video signal. I know that Windows Media Player has a Black Level adjustment.