This doesn't seem to be a FOV changer, but a Zoom Changer.
FOV is when you stand in the center of a circle. Now if you turn around in a full circle you can see the full circle, right?
if you turn from left to right, you see a Field of View of 180 degrees
If you can see half way between front and side on BOTH sides, that is a 90 degree field of view.
FOV is measured in how much of that circle you can see at one time while staying in the center of the circle (without a third person view).
If you sit in your chair, the edges of your field of view on each side are around 65-75 on each side. To tell if you are cheating, put both hands beside your face straight out to each side. Start wiggling your index fingers on both hands and slowly move your hands around toward your front until you can see the motion of your fingers out of the corner of your eye. Peripheral vision is most sensitive to motion, go back and forth a few time from front to back and find the spots on either side that are your limit. Now look at your hands....maybe at most 135-150, 180 would be unlikely if not impossible.
The game Mass Effect:Andromeda has a FOV changer for the solo play as it is taxing on a GPU to alter that -- items across the screen will become
horizontally compressed (vertical stays the same.
Zoom, is taking a smaller and smaller rectangle (in truth slightly curved, like curved monitors), and blow it up...but it doesn't help you see any better on the
sides unless you are looking from a third person view -- even from a far away zoom in a 3rd person, someone can still be behind where you are looking from.
With 360FOV, you have no horizontal blind spots.
Animals have different types of eyes -- on the side for wide FOV to watch for predators, and some animals have both eyes facing forward to better pick out detail in front at a distance.
While a hint in BNS suggests changing your FOV to see more, BnS doesn't have a FOV change like Mass Affect Andromada -- it only has zoom.