The Luna Display dongle, when connected to a 27-inch iMac with 5K Retina display using Thunderbolt, turns the iMac into a full-fledged 5K display. However, Adam Engst found that it comes with a fair number of tradeoffs.

AstroHQ’s Luna Display dongle can transform one Mac into a secondary display for another Mac. This is similar to what Apple’s Target Display Mode does, but that feature works only with iMacs of a certain vintage as a second display. Luna’s Mac-to-Mac Mode works with a wider range of Mac pairings, such as side-by-side MacBooks.

At MacTech Conference, automation guru Sal Soghoian gave a talk in which he revealed how, with the addition of just a Luna Display dongle, anyone can use built-in macOS accessibility features to turn an iPad into a touch-sensitive custom controller for the Mac.

If you’d like to use another screen with your MacBook while traveling but can’t figure out how to arrange and support it, Jeff Porten has found a simple clip that attaches an iPad to a MacBook for use as a second display.

Astro HQ’s Luna Display dongle for the Mac turns an iPad into a secondary monitor via Lightning or Wi-Fi. Others have pulled off such an iPad-as-Mac-screen maneuver using software, but Luna’s hardware approach taps into the Mac’s graphics acceleration to improve performance.