Sony FX 6 Quick Start Manual page 140

Cine EI: Slog 3 exposure without a LUT
With the s709 LUT off, no LUT at all, Alister Chapman suggests exposing a white card at 61
percent.
You can make these values zebra settings that will appear on the waveform monitor:
Menu/monitoring/zebra/zebra level 1
Keep zebra level 2 at 100 percent if you need to judge overexposure.
The above levels are for a proper photographic 90 % white, 18 % gray card.
Expose white paper at 63 percent.