Correct me if I'm wrong but this video is useless to LCD owners and for TVs without an "HGIG mode/tonemapping off" option?
I've just gone with -4, 0, +5 for my ZD9, I took screenshots inside a Cauldron and outside in the desert sun and:
On 0, 0, +2 the overall image is too bright, and the cauldron mid-shadows (don't know how else to say that lol, not the darkest ones) are blown out. Its not bad or anything, its totally awesome and playable but you can keep the bright highlights and increase contrast overall by a bit by changing it (+2 gives ~1600-nit highlights according to HDR Helpers brightness measurements graph, the test image loses a tiny bit of highlight detail at +2, but I with anyway because my Sony tends to blow out highlights a tiny bit anyway so I wanted the extra brightness, plus the values in game are slightly higher than the test image values anyway so its inevitable to lose detail in this game imo).
-8, 0, 9 wasn't too dark for 99% of shadow details but the overall image was too dull outside in the sun compared to how bright the highlights were and turning down highlights just made the image lose "HDR pop".
- 2, 0, +3 was great in the sun and I nearly stuck with that, just a bit less crazy overall brightness but still popping. When I went into a cauldron though I realised there could be a better balance for dark scenes. So I settled with the following:
-4, 0, +5
Thats 1600 nits according to HDR Helper graph:
You can find his analysis here, which I've found good when combined with VT and the dutch (?) guy's advice:
Horizon Forbidden West HDR Settings
www.hdrgamer.com
So if you're on LCD and/or don't have a tonemapping off mode then follow this guide/graph. Basically set Brightness as low or high as you want to get back shadow detail/reduce overbright image and then set the Highlights to correspond with your TVs HDR 10% window peak brightness, so if you want to save time just leave Brightness at default then bump Highlights down or up a few notches depending on your 10% window value, maybe one below your 10% value if you don't want the highlights to be that bit blown out but a bit dimmer. If you own a Samsung then set it to the exact value as they preserve the most highlight detail generally and if its a Sony then I suggest one pip below your peak to avoid too much clipping.