Graphics Settings

• The first screens deal with the usual monitor and resolution options.
• Non-16:9 aspect ratios are supported, including 21:9. The only caveat is that cutscenes will get rendered at 16:9; i.e. with black bars on top or bottom. Normal gameplay is fine, though.
• Resolution modifier lets you dial down the rendering resolution (for more performance) while keeping HUD elements crisp at your monitor's native resolution. You can also enable super-scaling here by using values bigger than 100%. The range of options goes from 50% to 200%.
• Field of View can be set between 85% and 115%.
• The FPS limit can be disabled completely or set to a value between 30 FPS and 90 FPS, in steps of 5 FPS.
• Assassin's Creed Odyssey supports HDR monitors and has a special option to enable HDR on FreeSync 2 HDR monitors.

• The remaining options are more graphics detail-oriented, and there's a ton of them.
• Overall quality can be set to "low", "medium", "high", "very high" or "ultra high".
• Adaptive Quality is an interesting option. It lets you set a target frame rate (30/45/60 FPS), and the game will adjust its details settings automatically while playing to reach the target FPS value.
• The other options do exactly what they say, no surprises here.