The developers of Astropad made a button out of the iPad’s camera →

Astro HQ, makers of the popular Astropad app which allows you to use your iPad as a secondary (tethered) monitor for your Mac, have announced a very interesting feature for their new Luna Display product 1 called the ‘Camera Button’. They have essentially turned the iPad’s front-facing camera into a button for triggering the Luna app’s UI.

Savannah Reising for Astro HQ:

Our problem started three years ago when we were working on our first product, Astropad. With Astropad mirroring your Mac screen on your iPad, you end up getting a unique UI overlap. First, there’s Mac UI showing up on your iPad, coming from whatever Mac program you’re using, such as Photoshop or Sketch. On top of that, there’s the native iPad UI. So if we wanted to add our own Astropad UI, where would it go? We didn’t want to create a crazy matrix of conflicting UI, so we looked for a way to minimize it.

On the first solution:

Our first solution for this tangled UI was the Astropad “ring.” It’s a little movable ring that always appears on your iPad screen when you’re working in Astropad. Tap on it once brings up a sidebar with shortcuts and settings. Tap on it again and it disappears. But could we minimize our UI real estate even more? As handy as this little ring was, it still gets in the way.

On creating the button:

Our Astro HQ cofounder Giovanni Donelli said that the idea to turn the camera into a button came like lightning, “I had been staring at a white bezel iPad for so long, and I kept wishing there was another home button we could use. My eyes kept falling on the camera, and I really wanted to touch it!” Giovanni built an initial prototype of the Camera Button within an hour.

Quite ingenious.

Savannah goes on to point out a couple of the the obvious concerns that come from having an always-on camera. First, according to their analysis, “the Camera Button requires less than 1% CPU to run”, and is therefore energy efficient. Second, she goes on to say they have designed the app so that the camera only detects light coming in — all other data is blurred and never leaves the iPad itself.

This is a bold move. When developers have done things like this in the past, Apple has sometimes rejected their ingenuity. I’m not sure if Apple has exact guidelines against this interaction, but we’ll see if the feature gets to stay. After all, the privacy concerns are real, especially if implemented by not-so-honest developers. If it’s allowed, I can see the ‘Camera Button’ being replicated in short order by other apps.


  1. Whereas Astropad requires a cable, Luna Display is a hardware solution that plugs into your Mac and pairs with your iPad wirelessly to function as a secondary monitor.