can someone explain this, adjusting levels

[Vince Becquiot]

If it’s going to be played on a TV, then you “shouldn’t” follow that advice. The article focuses on video going to Web or mobile devices which are in the RGB color space

Vince

[Jeff Brown]

The problem is that when you convert video black (7.5 IRE) to computer black it actually translates as 16 RGB, not 0 RGB where it should be. Likewise, video white (100 IRE) translates to 235 RGB, not 255. So what you wind up with is less contrast, and blacks & whites that aren’t true.

This is a very misleading statement, although not downright wrong. The 0 vs. 16 issue is hardware and system dependent. If you capture DV video via firewire, zero is zero and white is white; there is no “conversion.” If you capture via certain capture cards, 7.5 IRE is translated to zero. It depends on what is doing the conversion to digital. There are a multitude of combinations of translation to and from the digital domain, which can result in various combinations of analog and digital levels. Even certain software can introduce level changes (Avid QuickTime, e.g.). An erroneous statement like that mars an otherwise instructive page.
And — this only applies to NTSC North American standard video. NTSC-J, PAL, and HD do not use setup (7.5 IRE black levels).

-jeff

[Tyler Smith]

so what should i be doing about the levels then? do i even need to adjust them to fall within any specific range or should i just adjust them in the even that the picture is too dark or too light?

[Vince Becquiot]

Again, if you are going to DVD for playback on television sets, you should only worry about the usual color and level correction.

But most of all, trust your eyes. If it looks washed out or overblown, then it is (on a broadcast monitor that is).

There are many issues that are not mentionned in this article. One major issue would be Premiere’s scope acuracy, another is that some consumer and prosumer camcorder capture “superwhites”, and if you are capturing from an analog source, you are bringing a whole new set of issues that can’t be detailed in a single post.

The biggest issue is that you often can’t trust what manufacturers call “setup”, both in cameras and broadcast monitors. In summary, good luck !

DV had an interesting series a few years back that may bring some more insight on the subject:

https://www.dv.com/columns/columns_item.php?articleId=196601411

Cheers,

Vince

Cheers,

Vince

[Tyler Smith]

thanks for all that info vince…when i wrote this thread i didn’t have the setting checked off for maximum bit depth (or rate) and that was a huge factor in getting a proper reading on my scopes.

i’ll just keep the levels above 0, and below 100 and it should be good….if only cc’ing was as easy as this.

t