Clipping Indicator Demo


musicvid10 wrote on 5/4/2014, 3:59 PM
HD version is now up and public after talking with the owner. Many thanks to Gordon Laing and for allowing me to use his footage from Vimeo.
NormanPCN wrote on 5/4/2014, 5:11 PM
If you wanna try, download the zipped file "zebra", unzip

Thanks Marco for your SCC presets. Very nifty.

I tried these on a current project and it pointed out to me how Color curves was fighting me to preserve vilde levels while adjusting contrast.
musicvid10 wrote on 5/5/2014, 7:50 PM
Marco, I hadn't even thought of Secondary CC to do this, but it sounds quite plausible.
Can you post some screenshots of the controls so I can try it in Vegas 8?
Marco. wrote on 5/6/2014, 2:56 AM
There's a snapshot of the two fx side by side. Sorry, the GUI of the legacy view is German.

You'll see the base of the trick is to use the low and high values of "Limit luminance" to define the area of clipping. Leave "Limit saturation" and "Limit hue" deselected and choose a color of choice for the indicator in the color wheel.

musicvid10 wrote on 5/6/2014, 9:56 AM
Thanks, Marco. I'll have time to play with it this weekend.

Here is a version of the demo with all color channels exposed, in addition to highlight and shadow clipping. Took quite a bit of work to figure out.

Highlight clipping registers as black.
Shadow clipping registers as white.
Red, Green, Blue channel clipping registers as solid colors; i.e., Red registers as solid red, Blue as solid blue, etc.
Some pretty wild effects. Grazie, you may want a shot of Scotch and Dramamine before you watch it! J

Sorry, it seems Youtube added some unintended blurring to this one.

VMP wrote on 5/6/2014, 1:51 PM
Just one question.

I do not understand the use of this tool. Yes you can see 'clipped' area of the footage. But what can one do to the clipped footage after that it is recorded? Unless it is raw as far as I know there is nothing that can be done to retrieve the lost clipped part of the footage. It is lost info.

You can turn down the luma but still that part will look washed out/ bland.

Keeping the zebra in sight and tweaking down the exposure during shoot is the only way to prevent clipping in the first place.
Unless you are solely referring to RAW post-tweakable footage.

Marco. wrote on 5/6/2014, 1:55 PM
If the peaks already clipped while shooting – you're done. That kind of indicators just warn you about levels which might be clipped when you later use same video on systems which are not capable of displaying super black and/or super white. It's these levels of 0-15 (footroom) and 236-255 (headroom) which are indicated as "clipped". Almost none system displays footroom (super black), some systems does not even display headroom (super white).

So the indicator will help you to ensure signals which do not yet clip will not clip later either.
musicvid10 wrote on 5/6/2014, 2:44 PM
"So the indicator will help you to ensure signals which do not yet clip will not clip later either."

Perfect explanation.
If the indicators were dynamic in the Vegas preview, and the indicator thresholds could be set in advance (say [16,235]), one would know instantly when some tweak or adjustment threw luminance or color outside the acceptable range. Simply adding a Sharpen filter will cause this!

With more broadcasters going to PBS-like standards (zero tolerance in luminance and color channels), this is needed now and going forward. For stations that still accept IRE-style material with chroma slop, one could merely turn the color channel indicators off or set a wider tolerance. This would be really neat.

Remember, though, this is just a Photoshop demo of what it "might" be like. Going to be exploring Marco's lead for an in-Vegas solution next . . .
VMP wrote on 5/6/2014, 2:56 PM
Ok thanks for the explanation.

So this is a tool to help limit the levels, rather than target and retrieve clipped footage info.

musicvid10 wrote on 5/6/2014, 4:41 PM
VMP wrote on 5/6/2014, 5:04 PM
If it is retrievable. :-).

musicvid10 wrote on 5/6/2014, 5:38 PM
Well,I may want to roll it off, drop the gamma, or apply an s- curve to make it look better. Lot of things better than leaving a hard shelf.
Dynamic indicators give instant feedback. I'll have a video link for you to watch later when I'm not on Android.
VMP wrote on 5/6/2014, 5:55 PM
Thanks musicvid10.

musicvid10 wrote on 5/6/2014, 11:39 PM

This is a Photoshop tutorial; what I'm talking about is addressed at about 5:40 into the first video.
musicvid10 wrote on 5/10/2014, 10:17 PM
Just want to let Marco know that your Secondary CC trick works quite nicely!
Detects out-of-bounds luminance at whatever threshold one chooses.
Marco. wrote on 5/11/2014, 3:21 AM
Glad you like it. I once made the Secondary Color Corrector presets for somebody else. Maybe it's possible to include color values or make another version for color values only. I never tried. Also I see I had to shift the luma values ± 1.
musicvid10 wrote on 5/11/2014, 5:24 AM
No way to isolate the primaries that I can see, unfortunately.
But for luminance clipping, it's da bomb.