WiP: Let it Snow… November 19, 2008Posted by William J. Meyer in Jack's Post-Production, Jack's Videos.
…let it snow, let it flour.
Last winter I took some sweet pics on an icy day and kinda played around with how to incorporate them into the movie. I knew that I wanted to use the four seasons in some manner, but not until I removed an early scene did I realize the seasons would work as a transition, allowing us to jump ahead a year in the story and bridge the time needed for the titular house to be built.
I wanted to add snow to the photos for the winter portion, just animate them a little, give them a little life. At first I was going to use a particle generator, but I haven’t had much luck lately with particle generators. Then I stumbled upon the idea of using flour. The following short video gives a brief rundown of the process. The below explanation gives more detail.
Fill a zip-lock bag with baking flour and shoot it against a black drop cloth. Open the bag below the camera’s field of view. The flour particles will shoot up (open the bag like you’re angry). Blow on the particles if necessary/desired. Shoot the drifting flour using a long lens to create interesting depth of field.
In After Effects, apply Knoll’s Unmult to the flour layer to create transparency from the black cloth. You might have to play w/Curves (stacked before Unmult) for cleaner results. Apply a Lens Blur to the footage and increase the Specular Threshold. Adjusting the Specular Brightness will give the brighter bits of flour that neat “nearly-but-not-quite glitter” quality you see in drifting snow on a clear, sharp day (at least here in Wisconsin).