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Channel shifting

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Eric ChardChannel shifting
by on Dec 8, 2010 at 12:31:28 am

I'm so out of practice!!! Tell me if this is the easy way to get a monochrome layer.

It's an imported, multi-color AI file. I applied SHIFT CHANNELS and set all channels to alpha.

Now, this works perfectly, but it seems a bit awkward. Is there a faster way? A way that maybe doesn't have a hidden pitfall? Or is this the bog-standard way of accomplishing this-- I don't need any shades of grey, just straight "camera-ready" art.

++++++++++++++++
"Putting the HARM in 'harmonica' since 2005."
++++++++++++++++


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Michael SzalapskiRe: Channel shifting
by on Dec 8, 2010 at 7:08:24 pm

If you're asking what I think you're asking, try the fill effect.
Or create a solid layer and use your layer as a track matte.

- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.


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Kevin CampRe: Channel shifting
by on Dec 8, 2010 at 7:16:20 pm

does the artwork already have alpha transparency (it sounds like it may).

if so, you could us the fill effect and 'fill' it with any color you wanted.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW


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Eric ChardRe: Channel shifting
by on Dec 8, 2010 at 7:27:15 pm

Yes, it has an alpha already.

The issue is how to get a glow to follow the evolving alpha edge of the Film Burn effect, without also being added to the existing alpha edge. My thought was that by using the DIFFERENCE blending mode I could pull a difference matte by temporally offsetting two identical 'burning' layers by a frame or two-- the difference between the two would define the edge of the effect. Since the original alpha didn't change, it shouldn't show up

I got something that works (had to use CLASSIC DIFFERENCE rather than just straight DIFFERENCE), although it took a fair bit of futzing around. Now that I have the edge defined in a new precomp, my new issue is I can't get it to look bright enough to sell the concept of 'burning edge'. Also, I'd prefer to have the edge be thinner, like 5 pixels, but getting it there is proving challenging.

Thanks for everybody's input--it's been very helpful, and hey, keep it coming!

++++++++++++++++
"Putting the HARM in 'harmonica' since 2005."
++++++++++++++++


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Kevin CampRe: Channel shifting
by on Dec 8, 2010 at 7:53:05 pm

if you are using the glow effect, you can set it to sample the alpha rather than the rgb. so you could add film burn and then add glow, just set the 'based on' property to alpha.

does that get close to what you are after?

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW


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Eric ChardRe: Channel shifting
by on Dec 8, 2010 at 7:56:14 pm

Wouldn't that glow the entire alpha, not just the NEW alpha bits?

++++++++++++++++
"Putting the HARM in 'harmonica' since 2005."
++++++++++++++++


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Kevin CampRe: Channel shifting
by on Dec 8, 2010 at 8:22:25 pm

yeah, but when you choose alpha, the glow colors get switched to the a-b colors. the default a-b colors are white and black and with the blending operator set to add (default), black will be ignored/transparent, so you'd only see the white glowing portion on the edges of the film burn.

the thickness and heaviness could be controlled by threshold, radius and intensity.

if you wanted to remove the black burning edges the film burn effect creates, add cc composite after the film burn effect, but before the glow effect.

i'm not sure this is exactly what you are looking for, but from your description it sounded like you wanted the just the edge of the film burn effect to glow as it resolved the image, and this seems to produce something similar.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW


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