I wonder if the render resolution was actually determined by the output resolution of the film recorder being used to get the sfx out onto film for display? I can't obviously find a film recorder that offers more than 8k on 65mm/15-perf.

As I've not seen anyone else mention it, I feel the need to point out that Digital IMAX (which is the vast majority of screens and showings) maxes out at 4K.

https://www.awn.com/news/framestore-puts-grave-face-harvey-d...

Tim webber says it was rendered at 4k. Which contradicts what I remember. If he meant 4k textures that would make sense. 4k textures might have been why renderman kept on OOMing though and we had to tile the render even more.

Also I don't know how they printed it back out to film. It might have been sent to hollywood to laser/print out.