1st tryout on using alpha... is it supposed to work even when the blend mode isnt active? like "add" gives me an alpha at 100% opacity like just alpha does...
shouldnt alpha (and other blend modes too for that matter) give you the black parts when it is at 100%?
this is what i did:
source was something like this: http://www.youtube.com/watch?v=vzSRVgF501M
put it in AEcs4, colored keyed it, and rendered as dxv, preserve
i just ask because, while it might be useful that the alpha blend mode works at 100% opacity, i think that for other blend modes it might not be so helpful...
alpha question
Re: alpha question
Hey Werlin
You are correct. When you are working with a clip that has an alpha channel, both Add and Alpha at 100% opacity will show all the opaque pixels, and punch holes where the alpha channel is. You will never see the black pixels, since you keyed them out in AE. If you want to see the black pixels in your specific example, just play the video as is in Add blend mode at 50% opacity to get the transparency, and then crank it up to 100% opacity to get the black back.
I hope that explains things a bit.
You are correct. When you are working with a clip that has an alpha channel, both Add and Alpha at 100% opacity will show all the opaque pixels, and punch holes where the alpha channel is. You will never see the black pixels, since you keyed them out in AE. If you want to see the black pixels in your specific example, just play the video as is in Add blend mode at 50% opacity to get the transparency, and then crank it up to 100% opacity to get the black back.
I hope that explains things a bit.
Re: alpha question
so i will have to have one video with alpha and one without, right?
im just saying it makes no sense that every blend mode, difference, luma, rotate, subtract, (except for the cube) functions in this way when at 100%, specially when most of them (like diference) are in their visual peak at 50% of the fader
im just saying it makes no sense that every blend mode, difference, luma, rotate, subtract, (except for the cube) functions in this way when at 100%, specially when most of them (like diference) are in their visual peak at 50% of the fader
Re: alpha question
In the case of that particular youtube video you linked to, no. Since it has 100% white and 100% black, you can just use the Add or Luma Key blending modes to get rid of the black parts. This is essentially the same as using a chroma key in AE.so i will have to have one video with alpha and one without, right?
What happens is that you are mixing two layers together, very similar to mixing colours in real life. Just like with colours, when you mix all your reds and no blues, you get red. When you mix all your blues and no red, you get blue. Only when you mix half your red and half your blue, you get purple.im just saying it makes no sense that every blend mode, difference, luma, rotate, subtract, (except for the cube) functions in this way when at 100%, specially when most of them (like diference) are in their visual peak at 50% of the fader
When changing the opacity for the top layer, at 0% opacity the bottom layer will be fully visible, at 50% they both will be mixed together with blend modes applied, and at 100% the top layer will be fully visible. Since this indeed can be confusing or counter intuitive at times, we've added the 50 Add, 50 Mask and 50 Lighten blend modes, which do work in the way you describe and expect.
I hope that explains things a bit.
Joris