MSPU has a good write up, including:
The HoloLens field of view issue has been preoccupying Microsoft for some time, and they have been exploring a number of solutions, which tend to show up in their patent filings.
As Microsoft writes:
This discussion relates to complementary augmented reality. An augmented reality experience can include both real world and computer-generated content. For example, head-mounted displays (HMDs) (e.g., HMD devices), such as optically see-through (OST) augmented reality glasses (e.g., OST displays), are capable of overlaying computer-generated spatially-registered content onto a real world scene. However, current optical designs and weight considerations can limit a field of view (FOV) of HMD devices to around a 40 degree angle, for example. In contrast, an overall human vision FOV can be close to a 180 degree angle in the real world. In some cases, the relatively limited FOV of current HMD devices can detract from a user’s sense of immersion in the augmented reality experience. The user’s sense of immersion can contribute to how realistic the augmented reality experience seems to the user. In the disclosed implementations complementary augmented reality concepts can be implemented to improve a sense of immersion of a user in an augmented reality scenario. Increasing the user’s sense of immersion can improve the overall enjoyment and success of the augmented reality experience.
The latest patent, filed in June 2015 and published on the 22nd December 2016, is for COMPLEMENTARY AUGMENTED REALITY, postulates using a number of projectors to project images on the environment around you.
Crucially the images would be pre-distorted to complement your expected field of view from your HoloLens headset and would also take account of the depth map of the environment to intelligently change the images produced.
What seems incredibly clunky and unrealistic today might, in ten years, become photo realistic and robust enough to be confused with reality - think about the progress in smartphones from 2006 to 2016, for example. QVGA screens to QuadHD, 100 pixels per inch to getting for 1000. Where might this 'Converged Augmented Reality' (CAR) be in ten years' time? I doubt we'd then have a HoloDeck in every home, but I'd bet that we have HoloDeck experiences in museums and tourist attractions at the very least, plus consumer solutions for the well off who want to experiment in their own garages and offices.
So yes, step one of a hundred, but we're getting there. Now where's Commander Data and his Sherlock Holmes deerstalker?