When setting up a Raven with an iMac there are a couple settings that will need to be changed.
1. Make the Raven the Main display by dragging the "Menu Bar" over to the Raven screen and make sure it is the furthest left screen.
2. UnCheck "Displays have separate Spaces" to make sure only the main screen has the "Menu Bar". This will make sure Raven knows which screen is the main.
3. Open the UPDD Hardware Settings and set the Main display to Monitor 1.
4. Be sure your display resolution is set to 1080p on the Raven screen, by holding option and clicking the "Scaled" button in display preferences.