iMac System Preferences: The Displays Pane
If you use your iMac for heavy-duty game playing or you work with applications like video editing and 3-D modeling, you probably find yourself switching the characteristics of your monitor on a regular basis. To easily accomplish switching, visit the Displays pane in System Preferences (see the following figure), which includes two panes:
Display: To allow Mavericks to choose the best resolution for your display, select the Best for Display radio button. To manually select a resolution, select the Scaled radio button and then choose the resolution that you want to use from the Resolutions list on the left. (In most cases, you want to use the highest resolution.) If you have an external monitor connected to your iMac, click the Detect Displays button that appears to scan for that monitor. Drag the Brightness slider to manually change the brightness level of your display, or select the Automatically Adjust Brightness check box to allow Mavericks to dim or brighten your display as necessary.
Select the Show Mirroring Options in the Menu Bar When Available check box if you’ll be using multiple monitors or a projector with your iMac. If you’re using multiple monitors, each display has a dedicated Finder menu bar, and the Dock appears on whichever display you’re using!
Ready to stream content to your TV directly from your iMac — without cables? You can use the wireless AirPlay Mirroring feature to send the display from your Mac to your HD-TV. AirPlay Mirroring requires an Apple TV unit that supports this feature. You can also send the audio from your iMac directly to an AirPlay-enabled receiver or speaker system.
Color: Your iMac can use a color profile file that controls the colors on your display. This setting comes in handy for graphic artists and illustrators who need color output from their printers that closely matches the colors displayed by the iMac. Click the Calibrate button to launch the Display Calibrator, which can create a custom ColorSync profile and calibrate the colors that you see on your monitor.The Displays pane allows you to change monitor resolutions in a jiffy.