If you want your image to look decent or want the video perspective to come from above your desktop monitor (instead of that off-to-the-side laptop angle many of us are sporting), a proper USB webcam is in order.
If you’re not willing to wait for weeks or pay through the nose, what are you to do? There’s an app for that.
The Test Subjects
Searching around for use-phone-as-a-desktop-webcam apps that work with MacOS, I found two options:
- Iriun Webcam
- Kinoni’s EpocCam
Both apps require you to install a special app on your Mac, and they’re pretty spartan affairs: a single window with a video thumbnail and a named virtual webcam device appearing in other apps.
I also brought my iPhone SE out of retirement for one last mission.
App Impressions – EpocCam vs. Iriun Webcam
Because of its ads and limitations, EpocCam’s free version clearly isn’t meant to be used for any practical purpose. It exists only to prove that the tech works.
The tech… kinda works. It usually took a while to connect, and it wasn’t always able to recover after one side restarted. Sometimes I had to quit both apps, start the desktop app, then start the mobile app. I would hate to have to do that during a meeting.
Worse yet, I was never able to reliably connect via USB, even in airplane mode. It worked once or twice, but without rhyme or reason.
Apart from that, the app is adequate. There’s a video preview (when it’s not obscured by a fullscreen ad, that is) and buttons to flip horizontally, switch between front/rear camera, and turn on the flashlight. I’m not sure why you’d ever want to turn on the light.
Iriun Webcam iOS
Like EpocCam, Iriun has a button to switch between front/back cameras and a button to blind yourself with the flashlight. Unfortunately, there’s no horizontal flip.
Unlike EpocCam, however, Iriun reliably connected with both wifi and USB. I’m even able to keep the phone in airplane mode!
Just for completeness, I fired up both apps on my Pixel 3.
- Epoc has no UI controls at all, just a (squished) video preview, and it doesn’t autofocus.
- Iriun’s preview image geometry was also a bit off, but the app worked fine, and it has a few options, including camera selection. It also allows me to choose between my phone’s two front cameras; in the past I’ve noticed that few camera-using apps seem to bother with this. Unfortunately, wired use requires enabling USB Debugging.
Image Quality – 2018 Macbook Pro vs. 2016 iPhone SE
I’d like to thank my office mate for volunteering to help test these cameras. I think the image quality speaks for itself.
(Images captured from this webcam test page.)
It won’t win any awards, but this, um, rapidly prototyped approach is working nicely.
I put a little putty between the phone and the monitor to provide a bit of adjustability, plus tape to catch the phone if the putty fails.
Caveat and Conclusion
There’s one big caveat to using phones as webcams on MacOS: many apps won’t be able to use them.
Virtual webcams are apparently implemented as plugins, where the camera-using app has to load a library from the camera provider. The last few versions of MacOS have tightened security around plugins, and applications now have to specifically opt out of a security feature to use them.
I’m hoping there’s a better technical solution to this soon (so we can have our security and eat it too), but for now, this phone-as-webcam approach is limited to certain apps.
As of this writing, these apps will not work with virtual webcams:
- Zoom Desktop
- Slack Desktop
- Photo Booth
But these apps will:
- Microsoft Teams
- Quicktime Player
So if you want to use a smartphone as a webcam, or if you want to be a potato, I suggest you join your meetings in Firefox or Chrome.
Update: Enterprising redditors have discovered that it’s possible to workaround the security restriction per-application by unsigning the application bundle with e.g.
codesign --remove-signature /Applications/zoom.us.app. The wisdom of disabling security features like this is debatable, but in a pinch it will allow you to use virtual webcams with problematic Mac apps.