Sony have posted new firmware for the a7S Mk II designed to alleviate issues with sunspots. In Sony’s own words:
‘This utility updates the ILCE-7SM2 camera firmware to version 1.10 to address a condition where a black spot may occur in a high intensity lighting part of a shooting scene.’
Dark spots were ruining highlight areas, mainly for PAL-area users although the update also mentions some NTSC-area owners were facing the same problem.
The new firmware is available as a 250MB download from Sony’s site now.