BenQ XL2720Z - is this what to expect with motion blur?

[SC0TTRSS]

Received my new monitor last week; once hooked up, couldn't believe the different coming from 60hz to 144hz, the smoothness is very noticeable!, why I didn't do this years ago is beyond me! lol

However, it does seem to have large amounts of backlight bleeding which to be honest, I only really noticed when carrying out a few tests.

At Night with zero lights on:



Center room light on:




With lightboost/motion blur technology is this expected with these panels now?

Quote from Chief
"This isn't backlight bleed, but actually a normal artifact of LightBoost. LightBoost pushes the limitations of LCD more aggressively, which creates some amplified "backlight-bleed-style" artifacts similar to these."

It did get me concerned at first and was contemplating returning it, but after reading from the experts, i'm not too sure.

Would you say this is excessive? normal? or can be adjusted within the settings?

Thanks

[masterotaku]

Your monitor behaves the same way as my XL2411Z. In general, I noticed that the higher the Hz, the higher the gamma. I had to tone it down in the monitor and/or desktop. Because I don't have yet the new firmware, I'm using Lightboost at 10% as a substitute. It messes up the colors (purple-ish) to compensate the color of the 3D Vision 2 glasses, and worsens the contrast (dark colors are brighter, black is not black). Colors in motion blur reduction look the same as non strobed, but brightness is lower and motion blur is greatly reduced (when it's fixed).

Not related to everything I said before, the top left corner of my monitor is somewhat darker than the rest of the screen. For example, here: http://jasonfarrell.com/misc/deadpixeltest.php

Red screen looks very homogeneous.
Blue screen too.
But the green screen looks darker at the top left corner. I have to look from a bit above my usual height to see it "normal".

I'm not at home, but I have photos that show that.

[Chief Blur Buster]

Quote from Chief
"This isn't backlight bleed, but actually a normal artifact of LightBoost. LightBoost pushes the limitations of LCD more aggressively, which creates some amplified "backlight-bleed-style" artifacts similar to these."

Based on my experience, your monitor is normal at this price range. I have worse uniformity than that on some of my 6 monitors sitting here.

Note: The uniformity pattern can change when turning on/off motion blur eliminating strobe modes (e.g. BENQ Blur Reduction). Amplified horizontal bands can show up during LightBoost / BENQ Blur Reduction operation. It's likely an artifact caused by the timing asymmetry between continuous LCD scan-out (in the dark) versus all-at-once backlight strobing (flashed on fully refreshed LCD frames, but the LCD pixels at the bottom edges are fresher than the top edge). This tends to amplify horizontal band "bleed style" artifacts and is commonplace on 120Hz/144Hz monitors.

[SC0TTRSS]

Based on my experience, your monitor is normal at this price range.

Thanks for the reassurance Chief. Appreciate it

[srsbsns]

I would give the monitor some time to break in. Don't be discouraged like I was. After about 100-200 hours of on time the back light calms down and the black luminescence improves some. What you should be worried about is getting one that has really great black levels out of the box. I went though about 6 of these monitors thinking I would find a golden one. I ran into a few that had amazing blacks but they have a problem where they can only do like 1.9-2.0 gamma. Wondering if they were not getting enough voltage to the panel. Monitors like yours with poor black luminescence are better. They have better RGB coverage and gamma. Mine started off at 98% RGB coverage but after it broke in it gets 100% RGB.

[winnoe]

I would give the monitor some time to break in. Don't be discouraged like I was. After about 100-200 hours of on time the back light calms down and the black luminescence improves some. What you should be worried about is getting one that has really great black levels out of the box. I went though about 6 of these monitors thinking I would find a golden one. I ran into a few that had amazing blacks but they have a problem where they can only do like 1.9-2.0 gamma. Wondering if they were not getting enough voltage to the panel. Monitors like yours with poor black luminescence are better. They have better RGB coverage and gamma. Mine started off at 98% RGB coverage but after it broke in it gets 100% RGB.

Hmmm, this makes sense. My 5 year old Hp 2207w 1680x1050 60mhz seemed to have better colors than my 5 day old Benqs Xl2420z.

Does having 120/144mhz inherently cause colors to look a little less "pop" than 60mhz? I know Blur Reduction is an instant grey-out, but increasing the Mhz shouldn't,am i right? Maybe my Benqs need some time to get "broken in".

[srsbsns]

I cant remember the technical reason why but, yes. The higher the refresh rate the lighter colors and blacks seem to get. This also happened on my Asus VG248QE 144hz monitor so I assume this is normal for TN panels.

[Chief Blur Buster]

I cant remember the technical reason why but, yes. The higher the refresh rate the lighter colors and blacks seem to get. This also happened on my Asus VG248QE 144hz monitor so I assume this is normal for TN panels.

A faster refresh cycle means less time sending voltage to each pixel.
Most LCDs default to white (or black) when there's no voltage. You need voltage to create the opposite color black (or white). But a faster refresh cycle, when you refresh each pixel one at a time, left-to-right, top-to-bottom, you have less time to inject voltage into each pixel per refresh cycle. So LCD color gamut tends to go down, as you raise the refresh rate of an LCD. So the contrast between black and white goes down when you have less time to inject voltage into each pixel.

TL;DR: Because of more time sending voltage into pixels at lower refresh rates, you get more saturated colors at 60Hz, and less saturated colors at 144Hz. At 144Hz you have less time, so contrast ratio goes down (e.g. brighter blacks and/or dimmer whites, depending on LCD)

[winnoe]

TL;DR: Because of more time sending voltage into pixels at lower refresh rates, you get more saturated colors at 60Hz, and less saturated colors at 144Hz. At 144Hz you have less time, so contrast ratio goes down (e.g. brighter blacks and/or dimmer whites, depending on LCD)

Hey Chief,
So does that mean it would make sense to operate with a higher contrast (like 65 instead of 50) for 120/144hz?

I would like to have richer (or as rich as possible for TN) colors, but don't want everything to look like a cartoon/WoW palette.

[Chief Blur Buster]

Only up to 50.
Because on the BENQ monitors, the contrast starts clipping at above a certain level, so you don't see all colors in the Lagom Contrast test -- don't go above a certain contrast level or the colors start blending into each other...

http://www.lagom.nl/lcd-test/contrast.php