Blur Busters Forums

Chief Blur Buster wrote:Different refresh rates and different Vertical Totals can indeed amplify inversion artifacts to an extent. Interesting that inversion is worse at 182Hz -- maybe it's uncalibrated for that refresh rate. I wonder if there are Service Menu options to adjust inversion...

P.S. Hand-pursuited cameras can be quite challenging. I suggest the "Sliding Tupperware Technique" for zero-cost pursuit cameras -- it actually achieved remarkable accuracy. (camera taped to the bottom of an upside-down plastic container that slides across a slippery laminate desk/counter)

Is there a chance the artifacts are actually the result of a bad taken shot by the camera?

b0t wrote:Is there a chance the artifacts are actually the result of a bad taken shot by the camera?

Occasionally, yes, but probably not in this particular instance.
Excessively long exposures will create more ghosting artifacts than seen by eye (e.g. an exposure captures more than 1 refresh cycle, or the edges of 2 refresh cycles overlaps the same exposure). But would blur/mask any inversion artifacts.

Another test:
Inversion artifacts probably show up at both 180Hz and 240Hz for different pixel speeds (change 960 pixels/second). Inversion artifacts occur during odd pixel-per-frame (ppf) steps. Inversion artifacts disappear during even-numbered steps.

So it's possible 180Hz and 240Hz may not have differences in inversion artifacts, just a byproduct of an odd-numbered "ppf" value.

Try testing slightly faster/slightly slower motion speeds a bit and see what happens.

Did you adjust the od-gain setting in the factory menu (press button 4+5 during startup) to see if that helps decrease the amount of inversion artifacts? I can see the issue on your photo but I cant reproduce that on my own monitor as well with the same settings. I do see a small amount of flickering between the ufo's that is solved by lowering od-gain to around 20.

Chief Blur Buster wrote:
Inversion artifacts probably show up at both 180Hz and 240Hz for different pixel speeds (change 960 pixels/second). Inversion artifacts occur during odd pixel-per-frame (ppf) steps. Inversion artifacts disappear during even-numbered steps.

Yes sorry, I have not indicated that the pictures are taken with set speed of 960px/s. At different value (i.e. 1080 pixel/sec) the vertical lines are barely visible or sometimes completely disappear

Yes, 960px/sec (approx) creates an odd pixel steps at 180Hz
Likewise, I think 1200px/sec would create an inversion artifact at 240Hz

I'll have to think about how to optimize TestUFO to enforce even/odd pixel steps.

Chief Blur Buster wrote:Yes, 960px/sec (approx) creates an odd pixel steps at 180Hz
Likewise, I think 1200px/sec would create an inversion artifact at 240Hz

I'll have to think about how to optimize TestUFO to enforce even/odd pixel steps.

Can you please explain why?

and why is 960px/sec the most common test speed ? any parcticular reason?

960px/sec is the default TestUFO speed because:
-- It's the closest speed to 1000 pixels/second -- while exactly divisible by 60Hz, 120Hz and 240Hz
-- It's fast enough to see benefits of LightBoost, ULMB and other Blur Reduction.
-- It's easiest to interpret the "Blur Busters Law" on this:
Add +1ms of persistence = +1ms of strobe length = +1 extra pixel of motion blur per 1000pixels/sec
This is clearly seen with LightBoost 10% vs 50% vs 100%, and also adjustable with several BENQ and ULMB monitors too (Duty Cycle settings)
-- It's easy to do pursuit camera tests at this speed.
-- It spends long enough on the display to observe (2 seconds from left edge to right edge on 1080p display)

Too fast, and it's too hard to eye-track or do pursuit camera testing.
Too slow, and you don't see display limitations easily.

That said, for 4K displays at 1:1 DPI scaling, it's a good idea to double the speed -- TestUFO testing at 1920 pixels/sec instead. Double the resolution, double the speed, to maintain approximately 1-screen-width-in-2-seconds.

To understand inversion better, study the Techmind and Lagom articles at the top of www.testufo.com/inversion ....Most inversion patterns are alternating at even-number widths (e.g. checkerboard pattern), so using odd offsets will cause stationary inversion artifacts because voltages are no longer alternating to prevent the LCD pixels from becoming unbalanced. Every refresh cycle, (sub)pixels are positive voltage, then negative voltage, then positive voltage. Often in a checkerboard pattern.

By the way,how do connect the monitor to get the full 240Hz? Back in the day I used DVI-D for my vg248qe (people reported HDMI running 60hz only for some reason)

b0t wrote:By the way,how do connect the monitor to get the full 240Hz? Back in the day I used DVI-D for my vg248qe (people reported HDMI running 60hz only for some reason)

The monitor can run 240Hz with all three input types (HDMI, DisplayPort, DVI-DL), but your graphics card driver / operating system might not offer you the 240Hz setting out of the box (or the setting does not work reliable like, e.g., with Win7-64 + AMD Radeon RX460 + DisplayPort), even if the graphics card would be up to it. In this case, you can use ToastyX's pixel clock patcher and CRU to add a 240Hz resolution.

StrobeMaster wrote:

b0t wrote:By the way,how do connect the monitor to get the full 240Hz? Back in the day I used DVI-D for my vg248qe (people reported HDMI running 60hz only for some reason)

The monitor can run 240Hz with all three input types (HDMI, DisplayPort, DVI-DL), but your graphics card driver / operating system might not offer you the 240Hz setting out of the box (or the setting does not work reliable like, e.g., with Win7-64 + AMD Radeon RX460 + DisplayPort), even if the graphics card would be up to it. In this case, you can use ToastyX's pixel clock patcher and CRU to add a 240Hz resolution.

Ok thank you, but do I get any limitations being connected with DVI compared to DP? Beside DVI's lower pixel clock limit and the need to patch it?