BetterDummy Unleashes Screen Definitions on Apple Silicon Macs | MacGeneration

Using an external display is usually limited to plugging your Mac into it and selecting the resolution you want in System Preferences. Except that with screens in a format that is a little out of the ordinary, it sometimes happens that you don't find the right shoe, especially with Apple Silicon Macs that manage fewer different definitions.

The first thing to try in this case is, still in the Display settings of the Monitors panel, to click on the "To scale" option while holding the Option (⌥) key. This unlocks additional definitions.

If you still can't find a suitable definition, try BetterDummy. This free and open source application was created by Istvan Toth, one of the developers of the excellent MonitorControl. He designed it specifically for Apple Silicon Macs (although it partially works with Intel Macs) where he couldn't select a suitable resolution for a Lenovo 24" QHD (2560×1440) external display. pixels).

BetterDummy uses a trick to unleash the possibilities: the utility creates a virtual screen which then allows you to apply to the external screen, or even to the internal screen, all kinds of different definitions. For example, you can select a “Retina” definition of 1,920 × 1,080 on a QHD screen.

Several steps are required to take advantage of BetterDummy. In the application menu, you must start by creating a virtual screen (a "dummy"). This must correspond to the aspect ratio of the screen whose definition you want to modify. In the following example, I'm using a 16:9 Dummy.

Once done, go to System Preferences > Monitors. You will then see a new screen. Click on “Display Settings”, select the Dummy 16:9 screen and choose the following options:

When done, change the "Use as:" option back to "Main screen".

From there, you can very freely change the definition of the external display either in System Preferences (click on "Scale" while holding Option) or via BetterDummy in the menu bar.

As this is a new hack, not everything is set up very well yet. The choices made in the Monitors panel are not always retained, in this case you have to repeat them until you obtain the equivalent of the capture above. You will quickly see anyway if the change of definition works or not.

I did my tests with version 1.0.13. A version 1.1 which should improve many points is currently in alpha (it is limited to 10 minutes of use, the developer wants it to be used only for testing purposes for now).

BetterDummy brings a lot of flexibility to the management of the display, it can be used in many cases, such as to use a remote Mac mini at the definition of its choice or to modify the definition of a iPad in Sidecar. Version 1.1 will go even further by notably adding a Picture in Picture mode allowing the virtual screen to be displayed in a window.

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