using Blender to mask bright scenes

Using the same technique as in this previous post, but running on Blender 5 on Mac Mini, 3840x2160 video for Unseen Earth was being rendered at around 15 fps using the ProRES LT codec. Apparently Blender still doesn't have GPU accelerated output codec support, and this is one of the fastest codecs as suggested by ChatGPT. The ProRES LT can then be re-encoded as HEVC using the py-ffmpeg-warp presets. 

Some more tweaks used were:

• Multiple masks one atop another to darken extremely bright areas,
• Using Shift-D to duplicate and then K to cut the mask
• Using an adjustment layer to increase contrast for the base layer. 

Edit: April 2026 - I now see that Blender 5 has "Curves" as one of the Adjustment layer modifiers - so, we can easily clamp bright regions using a "Curves" filter. And it looks like this has been there in older Blender versions as well.