I was messing around with HAC2 and Multiclient in windowed mode, and I tried to make the game as close as possible to the screenshot. I think the FOV is 110 degrees give or take what I think is a slight camera adjustment for every player, because the weapon in bottom half of splitscreen appears to have a higher FOV based on weapon placement onscreen (If you fire up Xbox CE and give both players assault rifles, you'll see what I mean). An FOV setting of 120 meets the bottom in weapon placement but has a really bad fishbowl effect. Because of this, I think the camera may be lower or something for bottom half players.

Screenie showing comparison between 110 FOV Halo and a screenshot from Xbox CE's IGN review from 2001: http://imgur.com/dAqVXek (Not embedded because it's the resolution of two combined monitors with the unrelated parts of the displays cropped out)

I was also messing around with multiple players via Multiclient, and I figured out how to have an X360 controller control one instance, and the KB/M control another. The only snag I've hit is getting both copies to be active windows at the same time, because the inactive copy freezes. Does anyone know a way around this? I'm interested because I run a dual monitor setup and I play a few games with friends (including Halo Online :D ) with 'splitscreen', except I run one instance in each display.

Of course I doubt this works in campaign because the AI doesn't sync (so I've heard).