Ever noticed that burn you get on a PSP screen? I definitely have with my PSP-1000. I’m talking about the way in which fast-moving objects will leave small trails on the portable screen. This was especially noticeable with early PSP games such as ‘Ridge Racer’, and its car headlights. It’s this screen latency that’s used to the game’s advantage. PSP graphics have a habit of being home to sharp, jagged object edges. Any diagonal line (more-so when moving) will seem jagged, as if you drew it using Paint. It doesn’t look anti-aliased. It doesn’t look straight. It looks all bumpy and nasty.
Pixel lovers at ‘Beyond 3D’, have figured out Gran Turismo PSP’s ‘trick’. The game displays the normal racing scenario, but also moves the camera half a pixel every other frame. So there are two very similar images flashing together. With the game running at 60 frames per second, that’s 30 every second with a slightly different camera angle. If it weren’t for the LCD screen’s latency, the ‘vibrating’ image would be very apparent. But instead the two images, being left on top of each other, blend together. Using this method, edges look much smoother and more on par with PS2 graphics rather than PS1 or PSP.
Funnily enough, the final image was never used for any of the released in-game screens, which is why it looked so jagged in comparison to the final game. Weird. But still, nice to know how this stuff works.