Halo 3 running in 640p?

SIDEBAR: High-definition graphics have always been a major selling point for the Xbox 360, but the biggest title on the system to date, Bungie's Halo 3, might not even meet the HD resolution threshold.

That's the implication made in this thread from the graphics-centric Beyond 3D forums. In early August, a user going by the handle "one" posted a picture of Halo 3 with a jagged edge highlighted. Combining a little math and Photoshop, the poster came to the conclusion that Halo 3 was actually running natively at 624p, and being upscaled to run at 720p.

Bungie didn't address the issue initially, but it continued to stick in the craw of some graphics aficionados, who eventually came to the conclusion that the game was running in 640p. Today they have their answer, as Bungie finally addressed the 80p gap in its weekly Web site update.

The studio admitted in the update that "Halo 3's vertical resolution, when captured from a frame buffer, is indeed 640 pixels," but offered a deeper explanation as to why.

"[Y]ou could argue we gave you 1280 pixels of vertical resolution, since Halo 3 uses not one, but two frame buffers, both of which render at 1152x640 pixels," wrote a Bugnie representative. "The reason we chose this slightly unorthodox resolution and this very complex use of two buffers is simple enough to see: lighting. We wanted to preserve as much dynamic range as possible, so we use one for the high dynamic range and one for the low dynamic range values. Both are combined to create the finished on screen image."

The approach helps to give the game a "real" feeling at a steady frame rate, the update said, adding that the Xbox 360 can upscale the image to 1080p without a problem.

"In fact, if you do a comparison shot between the native 1152x640 image and the scaled 1280x720, it's practically impossible to discern the difference. We would ignore it entirely were it not for the Internet's propensity for drama where none exists. In fact the reason we haven't mentioned this before in weekly updates, is the simple fact that it would have distracted conversation away from more important aspects of the game, and given tinfoil hats some new gristle to chew on as they catalogued their toenail clippings."