Should one set their display brightness to maximum or 100% in the menu?
The answer is no most of the time, but displays typically come preset with their brightness set to 100% in the menu or On Screen Display (OSD). Figuring out the right balance between display brightness, room lighting brightness and display placement are key to ensuring a display looks as good as possible. Before going further make sure to read or watch my display placement guide IPS vs TN: Right & Wrong Ways To Use Or View; How To Vastly Reduce AHVA/IPS/PLS Glow & Increase The Perceived Black Depth:
Due to vertical gamma shift (uneven color from top to bottom) TN panels should not be used for comparing these photos, nor should displays with extremely low brightness outputting less than 80cdm/2 brightness.
All monitors were calibrated as well as possible using their menu settings with an X-Rite i1 Display Pro colorimeter and Spectracal C6 HDR2000 (October 2017 and beyond), matched to 140cdm/2 brightness and connected to a PS4 or PS4 Pro (late August 2017 and beyond). The same camera settings and same 15$ CFL Philips 2600 Lumen Daylight/6500k Light ceiling light were used for all photos. I use a colorimeter and change displays Brightness settings in the menu to output 140cdm/2 when measuring white since it pairs nicely with my 2600 lumen ceiling light:
Source image is a screen shot from The Order 1886 on the Playstation 4 by developer Ready At Dawn:
This level in The Order 1886 takes place at night and is meant to be very dark, but looks like a day time level when the Viewsonic XG2703-GS's default maximum brightness is used with my very bright 2600 lumen ceiling light. At 100% brightness the Viewsonic outputs 373cdm/2 when measuring white. The HDR standard advocates for 1000cdm/2 or lumens of the brightness of white, and the common brightness of house lights is 800 lumens or 800cdm/2 or less.
When the lights are off the monitors low contrast (1000:1) or high measured black depth becomes quite apparent. Lowering the brightness helps greatly, but the display is too bright and its contrast is too low for light-less use. A VA panel with 3000:1 contrast or higher looks fine in a light-less room if it only outputting less than 80cdm/2 white. Perhaps an OLED would look fine with high brightness in a dark room.