Our drone couldn't really fit anything wider, so we went with the average human IPD according to the rift SDK. You're right, at distance it's of no use. Closeup

Our drone couldn't really fit anything wider, so we went with the average human IPD according to the rift SDK. You're right, at distance it's of no use. Closeup, as we tried to illustrate with the pole, it helps. Aligning the cheap CMOS cameras were hard, though.