Question Portal 2 to bright (using lowest in-game brightness settings)


Dec 27, 2013

Just wondering if anyone knows how to lower a Valve games brightness lower than the lowest in-game setting?

I wanted to do another playthrough but the game is very bright even on the lowest settings so rooms on my last playthrough that were pitch black or now very bright.

I have this monitor:
I have set it to its recommend user specs using a monitor calibration website used by the community.
Prob the game as most old and new games are fine thou Valve games brightness are kinda out of whack.

Also had this issue in Witcher 3 to an extent.
If you're having this problem in more than one game it's possible your display and/or video cable is going out on you. That said, I've seen one person claiming this, showing comparison screenshots of his PC play, vs that he found of consoles, and most said (and I thought by looking at them) there was no such issue.

Best to post a screenshot so others can see. It may be something only you see on your end, and if that's the case, it could be a bad display or cable like I said.

If there's no hardware fault however, and you have the proper Dx and VS software installed, there is an extensive list of console commands that can be used, including gamma/brightness settings.

How to enable the console

List of console commands

I would suggest first trying the "mat_defaultlightmap" command, which by default is set to 1. Try a value of .9 first to see if it helps, then go down to .8, and so on. Note if you try to adjust brightness in game to fine tune after changing the default brightness value via the console, it may or may not override your console command, so I would avoid that if so.
Seems impossible assuming a modern HDMI, DIGITAL connection.
There's no such thing as "impossible" regarding video problems due to faulty hardware, especially considering the tons of crap quality HDMI cables and displays out there.

That monitor is also very low in brightness and contrast ratio, so it's only going to look worse in a darker lit situation with ambient lighting. That said, light placement matters a lot. This display looks very washed out if most of the light source is in a position that can reflect off the screen and make it wash.

This review shows how bad this display can look with typical office type lighting...
...just make sure you don't try to compensate with ultra low room lighting vs placement of light if you DO choose ambient lighting.

Normally I'd say if it is a hardware problem, it would more likely be the cable, as Dell's are usually pretty good, but this model is not reviewed so well. It could also be he's not running G-Sync on the game. G-Sync tends to look a bit darker due to the way it's implemented, so it may look too bright if it's off. You also need to be using the DisplayPort connection to utilize G-Sync.

If for some reason G-Sync isn't to your liking, this display also has Ultra Low Motion Blur mode, which lowers backlight level, but it's recommended for situations where your FPS is at least 85 - 120.

"If you’re not on the green team, or your setup is beefier, the Dell includes an Ultra Low Motion Blur mode. It works at 120Hz, and reduces backlight brightness and refresh in order to reduce motion blur to an absolute minimum. It works best on machines that can hold a constant 85 or 120 frames per second in games, and is incompatible with G-Sync, which has to be turned off before enabling ULMB."

After reading more about this monitor, I feel it's mostly it which is your problem. Even with ideal room lighting to make up for it's glaring flaws, you won't likely get a great result.
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