Background is "blinking" in animation render?

Hello everyone,

I’m new to this forum and I’m having a problem which is probably a simple fix but my understanding of Blender is limited. I’ve tried to upload the blender file but it was over 700mb so you can view the animation here (the background flashing starts at 0:22): https://vimeo.com/106376902

Everything works well in the animation except for the background. It looks like the light source is flashing which is very distracting and obvious. How can I eliminate this?

Thank you for your help!

I don’t think it’s related to the file size, but the color index. The gradient produced by your lighting, or background, is too fine to be supported by standard color palettes. the solution would be to eliminate that fine gradient. I think you can do this with the compositor, the same way that green screening is done. This would eliminate the need to re-render.
(edit) this phenomenon is called ‘banding’ btw.
(edit) oh, and if it’s the world background, you can usually fix the problem by using the dither settings in render buttons.

Thanks Modron! This really helped.

Case closed!