I recently start using sony a7s because I needed high iso.
I like the camera and the lens. Superior Sony FE1635 and some Canon optics with metabone.
The problem is mwb issue, very often getting error message if I'm trying mwb or I'm getting very poor color with what ever method I try (different PP or without).
So now I'm shooting everything with "underwater auto" which is just ok (getting lot of red with strong light or shallow).
And "Underwater auto wb" tend to change color reproduction (so they call auto) each time when I start record (this is more problematic in post).
I can reduce some red in post and possibly makes them usable but most of time I need throw them to client directly without post-edit.
Normally I do mwb on sand or other object and I didn't have any mwb problem with Canon DLSR (7D, 70D, 5D3) or Panasonic GH4.
Do I need more accurate white or grey card for Sony?
Any advice would be greatly appreciated.