ClickMonitorDDC

Very powerful, the latest version is archived on GitHub (without source code). Major disadvantage: Reset Display resets all (really all) display settings to factory defaults.

If the dev behind this ever comes here, please come back! ClickMonitorDDC was the best monitor control tool ever.

This application can be used as a simple tool, but if you want more - and I mean way more - it won't stop you.

Apart from setting contrast and brightness, it can set any value supported by monitor (help file also includes tutorial how to get non-standard value codes), including mode or color balance. So, at day you can have sRGB with proper brightness and at night non-sRGB mode, 0% brightness, 0% contrast and warmer colors. Either automatically (timer, application run or even more when combined with task manager), semi-manually (list of presets - just right click on the icon and choose preset!) or manually using sliders.

Another important thing is synchronization - if you want to use both monitor buttons and application, you'll find it nice that application can also read from screen and display current, real values.

It can even synchronize values in multi-monitor setup - so if you'd use buttons on one of the monitors, the rest will be synchronized. And if you have different hardware, you can set bias/differences, so it don't have to be the same percentage, but you can set them all to have same perceived settings.

And the thing that made me choose this application in the first place - it's very lightweight, with simple, but powerful GUI and it has customizable tray icon. As I'm using sRGB, I'm interested only in brightness and so my icon has only one value showing current setting.

This program dims the monitor on the hardware side, like using the buttons on the monitor. No grey haze.

Great app. Can change real monitor backlight brightness and other settings. Easy to set up and use.