I asked about the FOV (field of view), why it was lowered to 75 and was this the reason some people have been experiencing motion sickness while playing the game.


Hi xxx,

Thanks for writing. I'm glad that you've been enjoying Half-Life 2. As for the FOV questions: very early in HL2's development as our world got more detailed and fully realized we ran into some interesting issues that caused us to shift the FOV. Sometime in 2001 or early 2002 we made the decision to move to a tighter FOV, settling on 75 after some extensive testing. While FOV 90 is perhaps more representative of our visual experience in some ways - especially taking peripheral vision into account, in general a tighter FOV felt more accurate and appropriate for rendering the world and the objects in them given the goals we were pursuing in Half-Life 2. For example:

1) Characters all seemed frustratingly distant in FOV 90, and if you really tried to move up as close as possible to them, they'd be viewed with ugly wide-angle distortion on their faces - giving the experience an unpleasantly distorted or hallucinatory quality. And of course it was extremely unflattering to the characters!

2) Architecture and spaces feel oddly and unnaturally huge at FOV 90 - structures are unnaturally diminished at a distance, and it feels as if the player is moving at great speed through the world. In addition, every turn of the player's head emphasizes the distortion inherent in this wide-angled rendering, as objects move from the less distorted center to the extremely distorted edges of the screen.

We've been rigorously playing and testing Half-Life 2, Counterstrike Source and Half-Life Source for a long time now - and we've found nothing to suggest that the FOV change is a significant factor in causing motion sickness. We have, however, put a great deal of work and attention into reducing the motion sickness that can be experienced in the vehicles in Half-Life 2. During our early playtests, many of us were experiencing motion sickness from driving the buggy and the airboat - especially the airboat. We've done a lot of work on tuning the experience to reduce any ill effects - especially looking at how we manage the players head/view in relationship to the movement of the vehicles. Interestingly, for all of the vehicle sequences we revert back to FOV 90 so that you have more peripheral vision which is helpful when moving at these faster speeds. Even so, some people still do experience some motion sickness effects from long stretches in the vehicles - personally, I find that I am most affected by the intense jarring that occurs when you slam into something in the airboat at high speed - like when you miss a jump or something.

Thanks for the kind words about the game!

Best wishes,

Bill Van Buren
Valve