Sony A7s iii is 8 Bit HDR Posssible?

[benmiller]

Hi, I am really confused. Can't find an answer online.

I thought HDR content requires 10 or 12+ bit in order to be HDR. Isn't that the definition of HDR?

I shot some footage on my Sony a7s iii in 8 bit mode. When I view the footage on my Mac OSX Preview in Finder it gives a little HDR logo in the upper left corner. Also when I import it into a Rec 709 8 bit project in Final Cut Pro X, I get a warning that it is HDR footage.

Picture Profile is set to PP10 if that matters.

What is going on? Am I on crazy pills here or is there something I am missing?

Or is it perhaps that the picture profile is an HDR profile, even though the data inside it is not HDR?