Anyone who’s ever used virtual reality (VR), augmented reality (AR), or mixed reality (MR) goggles will likely have tried to explain to others what they’re seeing in their digitally reconstructed worlds. But there isn’t really an easy way of showing people what they’re experiencing without handing the headset over to someone else. And that’s why Microsoft has launched Spectator View, a new tool to help HoloLens users record what they’re seeing from a third-person perspective.
Microsoft launched HoloLens last year, a mixed reality headset that combines virtual and physical worlds using a rich set of sensors to create a spellbinding digital experience. There may be any number of situations that require an “audience” when using headsets such as HoloLens — for example, if you’re demoing something to clients or prospective customers — and that’s why Microsoft already offered mixed reality capture (MRC) to record what the wearer sees from their own point of view. But with Spectator View, you get to see what the HoloLens user is seeing while also enjoying watching their reactions. It basically serves to create a new experience altogether for those looking on from the outside.
Microsoft has put the necessary code on GitHub to help developers get started in creating their Spectator View camera rig, but all that’s really needed is a standard DSLR camera with HDMI output, and a PC through which the HoloLens connects over Wi-Fi. However, you will also need a second HoloLens device that connects to the camera rig. With that in place, you can livestream HoloLens content and capture photos and videos.

Above: Spectator View Setup
While it’s not for novices, those with the required development experience should be able to set the rig up themselves in “less than a day,” according to program manager Brandon Bray, in a blog post.
There are added benefits of using Spectator View too. MRC is subject to the head movements of the wearer, which can create unstable footage. But taking the same basic principle behind MRC and putting it into an external camera on a tripod fixes that problem.
Source: Microsoft’s Spectator View shows what HoloLens users see from third-person perspective