Blur Busters Forums

Chief Blur Buster wrote:

Ahigh wrote:With sample-and-hold what eye tracking looks like to your retina.
With backlight strobing what eye tracking looks like to your retina.

Just to confirm -- that appears to be strobing at 120Hz, rather than at 60Hz?

No, that's a 60Hz framerate on the Sony KDL-47W802A with a 1080p60 input signal in "Game Mode" with "MotionFlow Impulse" and a 1000hz camera (EX-ZR1000 camera)

The moving image is as sharp as a CRT. There is just a very very faint ghost image from the previous frame that is slightly visible. Other than that, no flaws at all in the motion portrayal that I can see. The ghost image is visible with a black background, but not really distracting. I imagine the ghost image would be less obvious with more than a black background.

All of these results would not have happened at all if not for the research from this page from the Chief:

Sony “Motionflow Impulse” reduces motion blur without interpolation

Ahigh wrote:The moving image is as sharp as a CRT. There is just a very very faint ghost image from the previous frame that is slightly visible. Other than that, no flaws at all in the motion portrayal that I can see. The ghost image is visible with a black background, but not really distracting. I imagine the ghost image would be less obvious with more than a black background.

Aha, now I understand. That's the inter-refresh crosstalk (which I now call "strobe crosstalk" -- the remnants of the previous LCD refresh leaking into the next strobe).

It is an attribute of most strobe-backlight LCD's. It varies depending on the panel, sometimes it's almost completely gone (e.g. there is nearly no inter-refresh crosstalk on the VG248QE panel in the center band in LightBoost mode, and only minor at the top/bottom edges of the screen).

The strobe crosstalk on most good, new strobe-backlight LCD's is faint enough that it becomes unnoticeable in the visual clutter of detailed panning imagery such as http://www.testufo.com/photo

I have four different strobe backlights sitting here (LightBoost, ULMB, Turbo240, and BENQ XL2720Z Blur Reduction), and all four of them generate slightly less to much less strobe crosstalk than what I see in your high speed videos, so I was curious. But yes, even the motion blur elimination is still very impressive even when there is a fair bit of strobe crosstalk.

A good test pattern to test for strobe crosstalk (ghosting) is http://www.testufo.com/ghosting



BTW, you might be interested in playing with pursuiting the camera (using a longer exposure & panning the camera while taking a photo) -- see pursuit camera instructions for more information.

Yeah, I was doing pursuit camera but just pursuing it like the cat was just using instincts and my limbs.

Regarding lightboost if it were compatible with g sync. Wouldnt the strobe effect feel weird since the FPS can change constantly? I'm pretty sure the eye will notice some difference between faster and slower strobe, maybe not if it stays above 72 fps or more which is around what the eye can perceive i believe.
Also is the fact that those 2 things not compatible hardware or software limitation or something else?

Renamed thread topic, to brand names.