x-xVA panel based LCD with no gamma shift?? (and what causes the shift?)

[RandomDude77]

Does it exist?

EDIT 2: What I'm referring to is the kind of shifting as seen here: http://hardforum.com/showpost.php?p=1034342905&postcount=18

I was strongly considering either buying the Eizo EV2333 or waiting for the FS2331, but I had read about the gamma shift issues of VA-
based LCDs and of Eizo in particular, and the user Whoisthisreally on here confirmed that the EV2333 indeed has gamma shift issues.

That really sucks.


Then, what about the new BenQ MVA displays with (w)LEDs? Would the LEDs prevent the gamma shift issue?

And on that subject, what causes the shift to begin with - is it the inherent nature of VA panels to have gamma shift or is it
the backlight coupled together with the VA panel that causes it? (if so, then perhaps a LED+VA display would have no shift?)


What about the Samsung F2380? It's a C-PVA panel. Has it any reported gamma shift?

EDIT: I just read on the PRAD review that it does have gamma shift.


The reason I'm not considering IPS at all is because of the horrible white glow issues (that are as strongly noticeable as the color shift of a TN panel)
and the poor black levels and weak colors (mostly based on my experience with the Dell 2209WA, but I've seen it on other IPS displays as well).

The price range I'm looking at is approx $340 to $680 (USD), size must be no larger than 24"... preferably 23".

 

[drtc]

have in mind the F238 has severe black crush issues.

 

[RandomDude77]

Yes, I know. I'm thinking that it might be corrected using QuickGamma. Then again, maybe that won't help at all. If the F2380 indeed has gamma shifting then certainly I'm not considering it.

 

[Drags]

it's down to the panel technology and pixel alignment in VA matrices,as opposed to the backlighting unit used. It affects all VA varients unfortunately, although not everyone notices it or finds it an issue

 

[Dainas]

All VA has gamma shift, however despite what some would have you believe not all VA are equal in gamma shift.

I personally could not stand the gamma shift on my Dell 2407WFP samsung S-PVA to the point of selling it, whereas I've found it soo minimal in comparison on my LG AUO P-MVA that its fits perfectly in with two HP LP2475w H-IPS on either side. Perhaps it was the poor contrast and blacks on the dell that just magnified it beyond reason, but for me the only way that dell could have been worse was if it was a TN.

Alas, should you ever feel bad about VA gamma shift, just remember that nomatter what some deluded souls may tell you here, VA is infinitely superior to TN in all measures that matter to a sane person with good vision.

This is moot though; Dells and HP's cheap eIPS offerings there is no reason to consider anything from companies who stick to VA panels, unless you have no choice due to location. Should you want the closest to viewing angle perfection, nothing short of NEC or Hazro's offerings with a A-TW polarizer will do, if you can track one down.

 

[Whoisthisreally]

I currently own the EV2333W and am considering returning it because of the stereo gamma shift issue. I was prepared to tolerate gamma shift across the screen, but at the distance required for a monitor, there is a fatiguing disparity between what each eye sees. As a first step, the retailer referred me to Eizo support, who then asked me to write down the issue in an email so they can investigate with their own stock on-hand.

My recommendation is to leave MVA for televisions.

As for the cause of gamma shift, it is an inherent trait of the vertically aligned LC directors. Once the director is tilted by the electric field, viewing obliquely further changes the tilt angle you see, thereby changing the lightness of a shade. Samsung wants to transition to blue phase by 2012, but the current polymer stabilised LC materials for blue phase have hysteresis, long term stability problems, and their voltage / transmittance curve fluctuates depending on room temperature.

Edit - After extended usage and evaluation I have decided to keep the EV2333W and am very happy with it. While MVA has compromised image stability, I feel that for most applications MVA exhibits good image performance.

 

[RandomDude77]

Of course, either VA or IPS is way better than TN... I traded my TN display for some dude's CRT which I'm using now (but it has some annoying issues).

Dells and HP's cheap eIPS offerings there is no reason to consider anything from companies who stick to VA panels

The reason I consider VA (mainly been looking at Eizo's) is because of the vastly superior black levels and colors in general. From what I've seen, IPS is very disappointing.
Instead of the gamma shifting of a VA (or the shifting of a TN), when you move your head just a few degrees off from dead-center, the brightness goes up / colors get whiter / contrast is lost...

Here's an extreme example of this problem: http://www.youtube.com/watch?v=-hOKgn_3iWs

It's possible that it's mostly e-IPS that has those issues, but I doubt it...

the closest to viewing angle perfection, nothing short of NEC or Hazro's offerings with a A-TW polarizer will do

I think I read somewhere that all IPS have the abovementioned problem and that only A-TW polarized panels are free from it.

Aside from them being very rare, they're way too expensive... the cheapest A-TW display I can get is the 2090UXi for around $1000.

 

[Jonte]

Here's an extreme example of this problem: http://www.youtube.com/watch?v=-hOKgn_3iWs

It's possible that it's mostly e-IPS that has those issues, but I doubt it...

Well, as you said, that's extreme.
Do you often sit in a dark room with no lamps at all staring at dark images?
In daylight, white glow isn't much of an issue at all.

Here's another video showing the glow (not always white as you can see) on three IPS monitors. The one that does best is the 2190 with NEC's own panel (no A-TW-polarizer there).

I think I read somewhere that all IPS have the abovementioned problem and that only A-TW polarized panels are free from it.

Aside from them being very rare, they're way too expensive... the cheapest A-TW display I can get is the 2090UXi for around $1000.

The 2090UXi doesn't have the polarizer anymore. The user Biges was lucky and got hold of some old stock. If you live in Europe, PM him and ask what store he bought from.
Last autumn some user here bought a refurbished 2090UXi, and he got one without the polarizer. I bought a second one in May this year and it actually had a new model name, the sticker read, 2090UXi-BK-1 (L). The Americans have updated their site as well with this name extension.


Why just not buy two screens, one cheap IPS (2209WA / W2220P) and the Eizo EV2333 or Samsung F2380?

 

[Jonte]

have in mind the F238 has severe black crush issues.

The screen was released a bit more than a year ago, how do you know they haven't done anything to adress that?
I find it highly unlikely that the version shipping now still has those problems. Eizo could fix it with their model based on the same panel, why wouldn't Samsung do anything in over twelve months?

 

[Snowdog]

Does it exist?

Then, what about the new BenQ MVA displays with (w)LEDs? Would the LEDs prevent the gamma shift issue?

It certainly does exist and it is inherent in the nature of VA screens. It has nothing to do with LEDs/backlights/screen coatings.

It is governed by the way the different LCD crystals control light passing through them.

MVA is actually worse than PVA despite what the marketing says:

Here is that new MVA panel (left) you are talking about next to in IPS panel(right).

http://www.pcpop.com/doc/0/569/569841_6.shtml

 

[RandomDude77]

Do you often sit in a dark room with no lamps at all staring at dark images?

Actually, yes I do. Not at pure black images, but I often have no lights on, and the lamps that are sometimes on are located way behind monitor (and for this reason I wouldn't mind a glossy/non-AG display at all). And even with the lights on (the room does turn rather bright with them on, it makes no difference in regards to the glow effect - can still see it just as much).

Also, it doesn't require a pure black image... Just any dark or darker part of any image makes it very noticeable. Only way to notice it less is if you source image is very bright to begin with. And just on a... let's call it a "medium" image - that is not necessarily dark or bright, but somewhere in between - or even just any random image/movie/whatever, the effect of the glow is always noticed straight away since the colors get washed out and turn brighter (regardless of their original actual color) as soon as you move your head a few degrees or more (and from there the glow increases exponentially). This is what I experienced on the 2209WA, and yes in the example YT video I put there the problem is worse and more pronounced than on the 2209WA, but for me the behavior of the effect on the 2209WA is extreme enough.

I don't get how people can be happy with that display, or any IPS that behaves like it (assuming all IPS have it - I've yet to see one that doesn't, if I'm wrong and there are IPS (non-AT-W) displays without the problem, or have it much less pronounced than the 2209WA, then please correct/inform me). . . Either they are coming from years of using crappy TN panels or some really bad CRT, or they are sitting completely glued in front of the display, 100% dead-center and never moving their head.

However, I noticed the glow on the 2209WA even without moving my head. Even sitting unnaturally with my head in a dead-center position, I could see the glow, as the center is closer to your head and the edges further away.

But that's just the glow, I found the colors to be weak and brightness was lacking (after fiddling with the settings for hours; settings which doesn't give you much choice to begin with), however that may just have been the 2209WA. There may be IPS panels that have much better colors, etc... I doubt it though.

I don't see a video in your post, you must have forgotten the link.

Anyway, thanks Snowdog; that's a good explanation.

 

[Biges]

Oh, oh, the infinite PVA vs IPS discussion. For some time, the choice had been clear - IPS with A-TW filter (not taking the price and speed into counting, there TN always wins). But no, stupid marketing departments could not sell this feature to people, so bye, bye NEC 2690/2490/2090 with great image (and HP LP2480zx and maybe some other less known monitors). I have NEC 2690 and a refub 2090 as a reserve monitor in case my 2690 gives up, I doubt I could use another LCD type (at least at home, at work I use dual MVA setup, no problem).

As for now, people just have to test monitor themselves, decide which negatives of IPS/PVA/TN they are most likely to live with.

Dell 2209WA has quite noticeable white glow, that is true.

You want to see why PVA has the gamma-shit?

http://www.personal.kent.edu/~mgu/LCD/pva.htm

Also:

 

[Walker]

Unfortunetaly, if TN shift and IPS glow bother you, there is a big chance the gamma shift of VA will bother you as well. Even with the glow issues, IPS still offers the most stable image at angles. VA may glow less on dark colors, but the loss of contrast and washed out image when moving your head just a few degrees off from center is quite more pronounced. I'm typing this on a PVA screen and I can easily see the edges on this forum are a different shade of gray compared to the center.

What bothers me the most about VA color shift however is that certain shades for whatever reason have a much more pronounced color shifting effect. So bad that each of my eyes sees a different color and I get a really weird "glowing" effect, as if it's confusing my brain or something. Makes me feel dizzy if I stare at it for some time Thankfully it only happens on certain shades so I don't see it too often during every day use. Probably only very few people will notice this but it's worth mentioning.

 

[Snowdog]

What bothers me the most about VA color shift however is that certain shades for whatever reason have a much more pronounced color shifting effect. So bad that each of my eyes sees a different color and I get a really weird "glowing" effect, as if it's confusing my brain or something. Makes me feel dizzy if I stare at it for some time Thankfully it only happens on certain shades so I don't see it too often during every day use. Probably only very few people will notice this but it's worth mentioning.

Yeah, that weird fake 3d drives me nuts. That is why I can't really use VA monitors. It took me by surprise when I bought my first LCD. Luckily most people don't have that problem and can use all the LCD types.