We have an analysis on FOV, or field of vision, on Battlefield 4, explaining how it affects target distance, area of awareness, and efficiency. For convenience sake, we’ll summarize the points below, and you can choose to read through it here or on the embed.
At 60 FOV ADS, it is easy to take a shot at a close target without doing anything else. At 90 and 120 FOV, however, the target seems to be much farther, although the actual distance stayed the same. Because of this, increasing the view makes it significantly harder to aim and make a precise shot. At ADS, at close range, it is best to stick to 60 FOV.
Zoomed in at 60 FPS, it is once again easy to take a shot at a close target without doing anything else. However, the view does not change when you switch to 90 or 120 FOV. Therefore, when you zoom in your sight, FOV defaults to a preset setting. In other words, there is no point to switching FOV when you are zoomed in.
Now, in terms of area awareness, 60 FOV gives you a very basic view of your surroundings. At 90 or 120 FOV, things seem much farther, but you get to see more of your surroundings, meaning you can see more of your enemies and where they are hiding, as well as obstacles, vehicles, etc. This also decreased draw distance, for the game to compensate for more images being rendered. Overall, there is no ideal choice in this situation, increase and decrease the FOV in a particular area to suit the needs of the moment.
A good rule of thumb is use a lower FOV when you’re making your way around a small map quickly, but use a higher FOV when sniping or playing slow. The high FOV makes it easy for you to check that no one is sneaking up on you, and when you zoom, you switch automatically to a low FOV, so you don’t have to worry about it. For quick games, a low FOV makes it easy to hit target even when you’re not zoomed in, and you can compensate for the lack of visual are awareness in other ways.