Creating Efficient Luminance Mattes in AE?

[Mark]

For this kind of work, I use change color, then isolate my color, then change the render view of the filter to matte….this creates a luma matte dependant on color. I can then play with levels or blurs on the matte and use it to luma matte other layers for such things as color correction, or color isolation. I often use this filter for chroma keying if i can not get a clean key.

Regards

Mark

[Andrew Kramer]

That’s a solid way to do it if you need the control. Just be sure not to use it when you don’t need to. Also, work in 8 bit (render 16) use lower resolution previewing and even skip frames. The most important thing is that your mattes don’t “crawl”, most of the time if the matte doesn’t crawl or seem noisy the color correction should be solid.

Use proxies for HD footage too.

Andrew
https://www.videocopilot.net

[Jay Lee]

Good afternoon Mark,
Thank you for your reply. A couple of questions if I may?
Are you applying change color to a duplicate of the footage or to an adjustment layer?
Not familiar with

[Chris Smith]

But if I understand correctly you want to isolate Shadows. midtones, and highlits as oppsed to specific colors, yes? Working with Shad, mids, highlits is considered “Primary” color corection then grabbing specific colors (what in Davinci is called a kilovector) is considered “Secondary” color correction and many colorists will tell you to always use Primary color correction for the main look with secondary for touch ups.

The closest thing you will get to good color correction in AE is the free “Color Finesse” plug-in. Look at the “Ranges” section. It is where you can tweak the barriers between the shadows, midtones, and highlits. But many people find the preset ranges to be perfect as is. Point being is that any decent color corrector gives you hue offsets for shadows, mids, and highlits without trying to reinvent the wheel with mattes. Everything you see on TV has been transferred using basic “primary” color correction (manipulation of shadows, midtones, highlights – both levels and hue offsets) adding power windows to isolate large simple feathered areas for overall treatment of an area, with secondary color correction to fix something that pops out (like too much red in a face or whatever).

[Jay Lee]

Hi Chris,
Thank you for takin the time to write.
I am actually well versed in CF and color correction in general after spending 100 of hours supervising telecine sessions.
CF is OK for primary color correction (has always been very buggy for me) but I am interested in exploiting other AE filters and effects on mattes selections such as blurs and glows.

Cheers,

J

[Mark]

I usually apply to a duplicate of the original, then I layer the matte, another duplicate and then the original.

Chris was right tho, I misread the original…..my method is for using colors to generate the mattes.

Have you tried usuing threshold on a duplicate ? This will allow you to isolate highlights and lows.

On the change color filter there is a view setting at the top that allows you to select to view the matte generated.

regards

Mark

[Chris Smith]

Ah, for FX and not correction really. I just use Levels and usually grab one of, or a mix of the color channels. It’s rare that I want the whoel mix of RGB the way it is. I’ll use the channel mixer set to monochrome then mix in the individual color channels till what I want isolated is the strongest. Then just add levels and crunch up the levels to define what I want to keep. This alone does most of the matting I ever need. I do this instead of keying most often. For example, to simulate trapcode’s Starglow, you copy the layer, crunch the hell out of the levels till only the brightest parts are still around, use hue/sat to bring the saturation back down, then add 2 layers of directional blur (for a star shape) then SCREEN it back over the original.

[Filip Vandueren]

The extract filter ha a bit more finesse than the threshold, offering both high and low ‘cut’ with variable slope, and it immediately results in an alpha channel (it’s in essence a double luma key)

[Aharon Rabinowitz]

Just want to point out that AE has many of the same color correction tools as photoshop, so if you have a mthjod that uses standard PS plug-ins, you may be able to recreate it eaxctly in AE.

In AE 7 the “Adjust” effects have mostly been moved into a section called “Color Correction”

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[Eugene Perepletchikov]

Another approach would be to use a layer stack of differing blending modes to isolate shadows, highlights etc… I find that you can achieve quiet subtle and complex colour schemes by carefully adjusting the colours through curves on each blending mode layer individually, whilst also variating the saturation so that your image doesn’t blow out. That way you can apply a blur just to highlights through a screen layer if you really wanted to, and still keep the shadows crisp, with all your tones carefully controlled.

This method may take a bit more time and fidgeting around (plus more layers) but in the end it can really pay off.

Good luck