This was an experiment to get a clean z-buffer. Normally I render the fractals at 1920 x 1080 with 2x anti-aliasing. This means that it renders internally at 3840 x 2160 and downsamples the framebuffer, smoothing out the jagged edges. Unfortunately, this process also smooths the z-buffer, which is never a good idea because it introduces unwanted artifacts when adding Depth of field in post. Usually I just take this for granted, but here I wanted to get it right, so I rendered everything at 4K without anti-aliasing. The entire post production pipeline had to be 4k as well, calculating the DOF also in 4K. I only downsampled to 2K at the end.
This definitely resulted in a much cleaner image, but it took a lot more work and time in post. I know I can use this trick when the image quality has to be absolutely spot-on.
Also, I used Particular in order to introduce some floating particles which felt like seeds from a pollinating flower.
Because I thought the bluish hue and alien forest looked a bit like Avatar, I used a track from that movie to complete the magic.