need to fix the sky

[Dorian Weber]

Thank you Kalleheikki,

please understand, that my knowledge in AE is very limited.
Could you give please me a few more details, so I could search for it?

[John Heiser]

I did just a quick and totally rough luma key to illustrate one issue you’ll have making the sky replacement look unified with the foreground. The cloudy sky adds a white cast to the buildings, which would be different if the sky were actually blue. I don’t have a solution to this, just pointing it out so your expectations are realistic.

John Heiser
Senior Editor
o2 ideas – Birmingham, AL

iMac Retina 5k, 27-inch, 2017
4.2 GHz i7, 32GB RAM, Radeon Pro 580 8GB
G-Speed Studio TB-2 12TB RAID-5

[Kalleheikki Kannisto]

A simple method would be to use the channel combiner effect. Copy your original footage so you have two layers with the same, add channel combiner effect. Use it to turn one of the RGB channels (the one with best separation between sky and flowers) into a black and white image. Then use levels to make it a mask with the flowers black and the sky white. Add your sky between two two layer and set the top black and white layer as an (inverted?) luma track matte for the sky. You may need to mask the buildings on the mask layer. Or you can mask them on a third copy of the original footage and place them as the top layer.

Kalleheikki Kannisto
Senior Graphic Designer

[Dorian Weber]

thank you John and Kalleheikki for your great advice!
I hope, I will be able to follow your instructions.

Many thanks.

Dorian