Chrispy_, excellent, you speak the same technical language;
Although Blur Busters focuses on the simplistic stuff, trying to educate the masses, I could write far more advanced articles, but it's so difficult to explain to people who think this is all display voodoo...
Yeah, agreed that "blur" as seen by most people is a combination of sample & hold persistance AND pixel response delay but in the interestests of simplification, especially with "1ms" gaming screens, pixel response is insignificant compared to the 16.7ms or 8.3ms of blur caused by sample & hold. It's actually more accurate to always descibe the blur or ghosting on non-strobing screens as "one uwanted frame", no matter what refresh and what pixel response your screen has. Whilst strobing effectively fixes blur or ghosting, it has nothing to do with fluidity of motion, only the perceived sharpness of moving objects your eye follows across a screen.
Yes, one way of saying that. It needs further expansion further, however:
1. Fluidity of motion without
-- Correct -- doesn't help -- you get strobe stepping effects of discrete framerates. Wagonwheel effects. Mouse dropping effects. (Move mouse in circles). It's not smoother with strobing. Strobing doesn't fix stroboscopic effects. In games, staring stationary at crosshairs while stuff passes in front of you, you may see stroboscopic effects of the finite framerates. You might even see the individual frames better and clearer (clearer stroboscopic effect) but smoothness is not improved.
2. Fluidity of motion with
-- In certain situations, strobing contributes to improved feel of smoothness: Perceived fluidity of motion during VSYNC ON framerate=Hz (120fps@120Hz) and eye tracking is accurate (e.g. saccade errors of less than ~1 pixelwidths). Example: http://www.testufo.com/photo
on a LightBoost display looks like "perfect smooth motion" (if using a browser that has working VSYNC). Much smoother than non-LightBoost 120fps@120Hz (because motion blurring tricks the brain to thinking it's less smooth, or from PWM artifacts
from multiple strobes per refresh).
Certainly, smoothness can become worse with strobing and tearing, since strobing can amplify visibility of microstutters and visibility of tearing (without motion blur to hide them). But with perfect framerate=Hz (VSYNC ON), there is no microstutters, and perceived smoothness can improve during strobing, as long as your mouse isn't the limiting factor in smoothness. e.g. Older source engine games are now generally capable of perfect framerate=Hz VSYNC ON now on modern GPU's; VSYNC ON running Source Engine games, on GTX680 and faster, currently have improved smoothness with LightBoost enabled. For this reason, I almost always play LightBoost with VSYNC ON on those games, with a good 1000Hz mouse, and make sure I sustain 100fps@100Hz or 120fps@120Hz to minimize input lag penalty of VSYNC ON as much as it allows.
G-SYNC eliminates the need to keep a perfect fixed framerate=Hz, so you get sustained smoothness whenever the refresh rate varies.
On a related subtopic -- some people track eyes during 180 flicks, while other people don't. Some have sufficiently fast eye tracking speeds to usually keep up with tracking objects during a 180 degree flick in first-person shooters, so it helps identify camoflaged enemies in bushes more quickly without motion blur, and stop mid-turn during a 180-degree flick (or even slightly slow mid-flick, shoot, finish flick -- essentially doing a 180 degree flicks while shooting enemies halfway for enemies 90 degrees off you, per se -- a select few gamers have that ability). If needed, suddenly seeing enemies that were 90 degrees the side of you, when you were just intending to reverse direction. However, some others religiously stare at the crosshairs, without much eye-tracking, during such situations. Benefit of a strobe-backlight-based display for a competitive gamer, varies from gamer to gamer -- it won't help everyone. Pro gamers used to staring at crosshairs (e.g. strafing and shooting things when it passes crosshairs) generally don't benefit from strobe backlights, while gamers used to eye-tracking (or games that force eye-tracking), the benefits of strobe backlight displays really show up (as we all already know from testimonials). And strobe backlights have the minor input lag penalty of waiting for a refresh to finish in darkness before strobing on completed LCD refreshes (high speed video
), but as we now know, it can improve reaction times in certain use cases to more than compensate for that (games that force eye tracking tactics) (e.g. testimonials
of improved scores during strobing).
The ultimate of the ultimate: Combining strobing with G-SYNC simultaneously. Gain the advantages of both. It's a very difficult engineering feat, due to the flicker risk of variable-rate strobe backlights. But probably a far simpler engineering fix than low persistence without light modulation (that requires ultrahigh update rates like 1000Hz if you don't want strobe/phosphor decay/subfields/temporal modulation of pixels). I've sketched a diagram of a variable rate strobing algorithm
that doesn't create low-frequency flicker. Just to be clear, this algorithm is being given away for free (only asking for credit, if anyone uses it). Although does nothing for smoothness during non-eye-tracking situations; fortunately it's not mutually exclusive: It doesn't make combining G-SYNC with strobing completely impossible. Wouldn't be nice to get everything; smooth variable frame rates, zero motion blur during eye tracking, zero tearing, no stutters, all at once!
[Quick-and-dirty napkin sketch diagram of variable-rate strobing without flicker -- an 'adaptive LightBoost' algorithm.]
Definitely, you're right -- strobe backlights mainly benefits eye tracking. However, lots of LightBoost users (including myself) would love to have both G-SYNC *and* strobing simultaneously.
...Now that G-SYNC monitors includes an optional NVIDIA-sanctioned strobing feature, it's not too entirely derailed to discuss trying to merge/combine the two (an engineering challenge).