how to do?

[Mylenium]

Well, that’s real pyrotechniques. It’s dangerous and mostly illegal for someone without proper training and permission, so I’m not giving any advice. Let’s just say there are enough tips and tricks on how to blow up your house, burn your face and chop of your fingers already on the net, so look eleswhere. The mattes can actually be created quite easily using luma mattes and unmultiplied luma channels.

Mylenium

[Pour Myl

[Martin]

Mylenium
Can you explain in a little more detail about the mattes…..
Thanks for the advise on the other I wont be going there
Martin

[Mylenium]

The simple way is to use a copy of the original footage on top and then set the matte mode of the lower layer to “luma matte”. This will kind of work, but you will need to adjust the alpha since noramlly this way you cannot get real-looking transparencies. The other method is to “unmultiply” the brightness. The assumption is, that a bright pixel will cover up any other pixels behind and thus all pixels of less brightness are transparent or semi-transparent. In a way it’s similar to luma mattes, but since it uses different formulas it yields better results. Plugins for this are e.g. XMult (free), Walker Effects Alpha Tool or Knoll Light Factory Unmultiply.

Mylenium

[Pour Myl

[Martin]

I used a some footaged of clouds.What I done; I used walker unmultiply but not to good!but Then I put the original footage on top of the unmultiply footaged then used track matte luma, not 100% opaque so I copied the footage but it’s gone a little darker in the transparent areas. Around the fringes of the clouds, showing a little color also.
Any more ideas…
Thanks
Martin