Sky Enhancement

In this composite I used nodes in Nuke to reformat cloud images to match the format of the background footage before using the RGB channels to identify which channel provided the most contrast for best results for keying and rotoscoping. I then applied a luminance key to each of the cloud images and changed they node to the proper RGB keyer. I adjusted the keyer nodes according to the alpha channel for the best possible luminance and transparency results. I then rotoscoped the clouds applying blur nodes for seamless transition. Merged in the results to copy nodes, graded, pre-multiplied, and transformed the results, I also defocused the images to match the background footage. Those results were merged over the background footage, the building and the tree rotoscoped and brought in front of the clouds I place to give the appearance that they were always there, all along.