The FOV of Xiaoyi camera is 150 degrees, so 3 cameras would be 3 x 150 = 450. Not enough..?
Yi, according to manufacturer specs, has 155° D(iagonal)FOV.
The actual Horizontal FOV is about 120°, the Vertical FOV is about 90° (my measure but quite right). You need at least 6 Yis to capture the whole sphere (i.e. 360°x180°) conveniently set like in this rig:
Kodak 360 is cheaper then 6 x YI cameras, takes way less space and no need for complicated brackets.
When you zoom in I think that makes a difference but I would like to know if I am right.
The gui control ap by Andy_ is good for shooting multiple Yis together but that implies the use of a pc which is not much comfortable when you have to move and take many outdoor still pictures.
A smartphone ap to do that for 6 Yis would be very, very good.
So many many thanks in advance to anyone (i.e. Luckylz or others) who will succeed in doing.