ADOBE PREMIERE PRO: Tutorials Forum Articles Creative Cloud Debate

White levels above 100...

COW Forums : Adobe Premiere Pro

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Oscar GottiWhite levels above 100...
by on Dec 10, 2015 at 11:07:40 pm

Hi all,

Just out of curiosity...

I've always wanted to know why some broadcasters won't accept videos with white levels above 100?

If the area above 100 is just over-exposed white, then why is that a problem for them?

Also, applying a video limiter for white levels is just making the over-exposed white less bright...The detail information is still lost... So why is that okay?

Thanks, just one of those questions I've always wanted to know...

Oscar


Return to posts index

Shane RossRe: White levels above 100...
by on Dec 11, 2015 at 12:16:45 am

An old spec for older TVs. Do you remember watching TV and when it hit some local commercial, that was really over exposed, there would be an audible BUZZ that came from the TV? Well, that's the issue. Whites that are above 100IRE can cause an audible buzz in audio. I won't say this doesn't affect newer HDTVs, because I have a 4 year old one in my bedroom, and when I play a certain VHS tape on it, one for the kids that is VERY hot (recorded off air), I get an audible buzz. So it's still an issue.

That's why there are restrictions on the white levels.

Shane
Little Frog Post
Read my blog, Little Frog in High Def


Return to posts index

Oscar GottiRe: White levels above 100...
by on Dec 11, 2015 at 11:43:41 am

Thanks Shane,

So in theory, if something hot was to go on-air today, would it be more likely to create buzz on an older TV, rather than a newer HDTV?

Nowadays, do most broadcasters have their own broadcast safe filter applied to all their content due to go on air?

Curious that your VHS video would give that buzz... Are you sure the buzz isn't embedded on the tape itself? also, not sure what you mean by 'recorded off-air'?

Sorry about all the questions,

Thanks,
Mayto


Return to posts index


Tero AhlforsRe: White levels above 100...
by on Dec 11, 2015 at 11:48:54 am

[Oscar Gotti] "Nowadays, do most broadcasters have their own broadcast safe filter applied to all their content due to go on air?"

Some might, some might not. Also they might either hard clip it or soft clip it, so it would be best that the footage is in order before you send it out. Some broadcasters might reject the file completely until it's fixed to the proper levels.


Return to posts index

Jon DoughtieRe: White levels above 100...
by on Dec 11, 2015 at 1:57:55 pm

It is often referred to as "sync buzz". The out-of-spec whites create distortions in the signal that bleed into the audio audio circuitry. Most commonly, this would be the IF coil. On old TV's where you had quick access to a brightness control knob, you could make it disappear by simply turning the brightness down, thus effective reducing signal strength in the circuit. On modern screens where you have to wander through menus, this is less practical as a solution.

Ultimately, broadcasters also pay attention to these signal specs because the FCC requires it.

System:
Dell Precision T7600 (x2)
Win 7 64-bit
32GB RAM
Adobe CC 2014 (as of 7/2015)
256GB SSD system drive
4 internal media drives RAID 5
Typically cutting short form from HD MP4 and P2 MXF.


Return to posts index

Tero AhlforsRe: White levels above 100...
by on Dec 11, 2015 at 2:05:51 pm

My friend had a TV that would shut completely off if there was something really bright happening eg. an explosion. It was a bummer when we we're watching action movies.


Return to posts index


Oscar GottiRe: White levels above 100...
by on Dec 11, 2015 at 2:41:46 pm

So do you still get sync-buzz on modern TVs? Or is just on old ones?


Return to posts index

Andy FieldRe: White levels above 100...
by on Dec 11, 2015 at 7:57:03 pm

There's another reason -- standard levels across all stations......how much fun would it be to switch from one station to the next (or from one scene to the next in a show and then the commercial) with levels all over the place --

Andy Field
FieldVision Productions
N. Bethesda, Maryland 20852


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2016 CreativeCOW.net All Rights Reserved
[TOP]