Render sphere surface to HDRI? I want to bake the surface of a sphere to a equirectangular HDR texture. Is this possible?

For baking I did not find an option to bake HDR. My approach was to use a sphere with backfaceculling and a panorama camera inside it, but that results in different lighting as the normals are different:



The surface parameterization should support baking directly to HDR. Am I missing something? Help? :D

Something that I tried was rendering it as a mirror ball panorama, but the conversion to equirectangular resulted in some artifacts.
When creating the image, check the 32 bit Float option:



Bake whatever you want into the texture, in your case you want the Combined bake type. I suppose your sphere is correctly unwrapped into a square layout.

Your texture will have the full dynamic range you need.

Save the texture in your favorite format (Image Editor, F3), .hdr is an option.