compositing smoke

[ollie slats]

Hello all!

Im trying to composite smoke and dust over a background plate, I will need to CC/Match to plate.

Its a QT element shot over black.

Im just not getting what I want too see, I seem 2 have this “black halo”, around the edges of the smoke, Im using the LUM keyer, I was hoping that someone with more experience, could give me some tips. Have have tried using the edge controls… it still looks cut out and pasted over the plate.

Slowly losing my mind.

thanks!

[shannones riders]

I guess you are using the same image as front and as matte as well. That’s why you have that halo. Forget the keyer, you don’t need it at all.

You have two options to solve this:

1./ simply turn the front off that media
in this case your smoke will be white (media with turned off front is white) and the smoke footage will work as a
matte
the problem with this is that you can’t color correct your smoke

2./ add a white image as front and turn it back on, now you can grade the smoke

you can color correct the matte as well, this way you can set the density of the smoke

Hope this helps.

[Walt Donovan]

u could always turn the matte off and use simple add or screen as the transfer mode too

[Allison Butler]

As mentioned, turn off the matte and use screen mode.

The real trick is to make TWO layers, one with screen mode, one with silhouette alpha mode. Place the silhouette layer below the screen layer and it will give you the density you seek without creating matte fringe.

You can also place a silhouette layer in front of the screen layer at 50 to 25% opacity to turn the smoke from white to any shade of gray.

ProTip: use a hue/saturation node on the white smoke screen layer and you can color correct the smoke to properly match its BG plate.

[Steven]

Hi,

If your dust element has been shot over a black background, I would suggest that you don’t use a luma key.

The better option is to select the image object in action and in the image menu, change the blend type from normal to screen.

That will eliminate all the back and you should have any black fringing on the edges.

Regards
Grant

[shannones riders]

@fxnerd 38271 wrote:

As mentioned, turn off the matte and use screen mode.

The real trick is to make TWO layers, one with screen mode, one with silhouette alpha mode. Place the silhouette layer below the screen layer and it will give you the density you seek without creating matte fringe.

You can also place a silhouette layer in front of the screen layer at 50 to 25% opacity to turn the smoke from white to any shade of gray.

ProTip: use a hue/saturation node on the white smoke screen layer and you can color correct the smoke to properly match its BG plate.

Wow, I tried this today and seems really promising, but still not as good as you describe. Could you clarify please what you mean by silhouette alpha? What is this layer exactly? How is it added to the background? What belnd mode?

[David Sekiguchi]

Yes, tell us more… And tips for flame/fireball comps.

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