The idea of BFI is to alternate between showing a frame of the game and a frame of pure black. This completely eliminates motion blur due to persistence, and can give you motion clarity similar to the old flickering CRT displays. If you're using a 120+Hz display, this software BFI demo might be helpful.
Some considerations:
- Ideally, the monitor would do all this by actually strobing the backlight (e.g. NVIDIA ULMB) instead of the game rendering black frames. However, most monitors don't have this feature or have a very limited implementation. Higher refresh rates alleviate the problem in a less complicated way, so backlight strobing is a relatively niche/poorly supported feature.
- Software BFI probably needs to use (and require) vsync to avoid microsutter.
- Software BFI may simply exchange some persistence blur with pixel transition time blur. However, most 120+Hz monitors should have fast enough response times to make software BFI a clear improvement.
- Depending on how the game's rendering works on a technical level, implementing BFI might be feasible or even easy. There is no obvious reason why BFI would be obstructed by the game's dependence on 60UPS in the same way that increasing the framerate is. It is possible that engine limitations make it too hard, but I figured it's worth suggesting just in case.