Irritating angular brightness shift & other issues


Mar 20, 2016
Hi all.

TL;DR or short story:

I'd like to ask you to take a look at a video and suggest some ideas, what are the root cause why an IPS monitor which is new, more expensive and feature rich shows so bad brightness shifts when looking at various angles, when compared to an older, less expensive IPS monitor.

(Sorry, I'm a new poster, cannot post direct links yet, so please go to Youtube and add the following URL to video)


Sorry for the quality and shaking, I didn't have a good camera at that time. I hope the quality is good enough to clearly show the issue.

If you have an IPS monitor, I would be grateful if you could shoot a similar video and publish it somewhere (Youtube, Dropbox, Google drive etc.). The process is simple and will take just a few minutes. Open any image editor (Paint etc). and fill it with single color (yellow works the best, in my experience). Then move your camera up and down to detect any brightness shifts, if they are present.

Also, I would really appreciate technical details and explanation why such shift is present in a new IPS monitor and not in the older one, so I can gain more knowledge what should I look for when buying a new monitor.

Is this shift caused by the fact that the bad monitor has LED backlight but the good one has CCFL? Or is it some fault in backlight vaweguide (if that's the right term; English is not my native language)? Or is it AG coating? Or is it caused by IPS LEDs themselves, in which case I wonder how can I know beforehand which IPSes are free of this issue?

What's confusing - a similar model to the bad monitor in my video in reviews received high scores for brightness uniformity. I suspect that the results might be different, if the test had included brightness shift measurements at different angles.
It would be great in the future to have such test for each monitor to evaluate vertical and horizontal radius at which brightness shift exceeds some value which might feel uncomfortable for users, and repeat the test at multiple distances from a monitor. I guess, near-sighted people would be grateful for such tests. Currently there are images of different viewing angles in each review, but they usually show an image of a beach, and it is hard to evaluate if the monitor is free from bad brightness shifts when looking at a colorful photo. The brightness shifts are most irritating when reading a text on a white page.

The long story.

I'm visually impaired since birth (nystagmus + astigmatism + near-sightedness). It's so bad that I have no chance to get a driving license. But despite that, I am really interested in computer programming - it got really serious and now I have master's degree in software development and now I have been programmer and software architect for 8 years.

Choosing a monitor has always been great frustration for me. To be able to work I have to have my eyes located closer to my monitor than "average user" (to avoid leaning forward and having bad posture, I'm using ergonomic arm which brings my monitor closer to my eyes and adjusts it the way I need). Also I have to use lower screen resolution. Such usage scenarios allows me to notice various kinds of flaws in monitors and graphics cards. As the result it is really hard to find a monitor which is comfortable to my eyes, so I can work for hours.

At first I thought that I should avoid flickering backlight because I'm in general very susceptible and notice flickering where "average people" don't. Therefore when I read in reviews that ASUS PA238Q monitor has higher backlight frequency, I thought - yes, that's the monitor which should be comfortable for my eyes. Also, knowing that it is IPS monitor, I put high hopes on its color and brightness uniformity and viewing angles because the Internet raved about it. Of course, I was aware that IPS panels have some other issues like pink/blue/gray backlight bleeding, especially noticeable on dark images, but I thought that I can live with that.

So I bought PA238Q and was somewhat pleased with it. Still, it had some brightness patches and shifts, especially noticebale from my normal viewing distance (30cm), and it had blotchy backlight bleeding, but I thought - oh, well, then IPS technology is not that far from TN, and I had too high hopes.

But then one day in my office I had a chance to work on Viewsonic VP2365WB and somehow subjectively felt much better. I immediately organized a test with both monitors and was really surprised how bad my new, relatively expensive PA238Q turned out to be compared with VP2365WB. Reading a page of text on VP2365WB felt much more like reading a text on a printed evenly lit page, while reading the same page on PA238Q felt like reading on my old TN monitor. Also, backlight bleeding on VP2365WB was much more even without distinct patches.

I went even further - I exchanged my PA238Q for another one with a hope that I got a bad device, but the new monitor was even worse - it had even more distinct backlight patches.

As the result I bought VP2365WB and gave my PA238Q to my sister who is using it as a TV - at a far distance this monitor is pretty good.

Now I'm afraid to think what will I buy in case if my VP2365WB dies. VP2365WB is discontinued and I'm not sure if new Viewsonic models are as good as this one. Maybe Viewsonic has some special know-how which they are sticking to, and the angular brightness uniformity is one of the things they try to provide in every model? At least, it's nice to see Viewsonic web site to advertise some eye-care features like flicker-free and blue light filter, and also their SuperClear description claims to have special attention for wide-viewing angles, but I'm not sure if they have done anything in addition to what IPS panels already provide, in which case they might have models with bad IPS panels which suffer from bad angular brightness shifts.

I'd like to try a flicker-free monitor (TFTCentral has flicker-free monitor database) but I'm not sure, how to find a model which is not only flicker-free, but also free from such irritating brightness shifts and blotchy backlight bleeding.

Thank you for reading this long text and I really hope someone with technical monitor knowledge will give an advice how to find out if a monitor has problems with patchy backlight and angular brightness shifts, even if reviews claim that it is fine.
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Cheap Ips vs Expensive Ips.

Love where he says the expensive one shows very little glow, yet they are basically exactly as bad.

It is what it is. ON your two samples, it could be different diffuser, the backlight type, panel..ect. Consistency is not really reality with lcds. Unless it's consistently crappy.

Backlit imo was better than edge lit. It was cost cutting and it's simply not as uniform in practice. It can be, when done right. Yet it hardly ever is.

Both of those panels in your video probably have similar matte coatings and panels, seems the thing most different about them is the backlight.

There is little difference in the grande scheme of things when comparing low to mid range monitors for general pc use. Gaming panels ect are at a premium for cutting edge speed and features ( a long with more headaches) and same panel inconsistencies.

So Imo go all in or go cheap.
High range for specific needs, seemingly based on your requirements I can only say one monitor. The Eizo cx241. It's $1200 dollars. But, if you use your pc every day, and you have special requirements, and comfort and quality is not just a luxury, but rather a need. Then there really isn't a better choice for uniformity and low/no glow, again I say this based on your seemingly stated needs. Yes it's expensive. But a quality display you will use for a long time. At $1200 dollars that's $200 dollars a year, for 6 years for quality, and comes with a 5 year warranty.

At 24" 16:10 you get more vertical space than 1080p. Medium/Average 1080p like Dpi for easier reading. You can sit closer to it. Best in class uniformity and color quality with little to no perceivable glow. There is nothing to compare it with really, besides it's higher priced siblings and some super expensive medical displays which actually have to conform to specific standards of greyscale contrast and viewing angles.

Same price as a medium performance PC, yet that pc likely doesn't have a 5 year warranty. :)

At Mid range -0 See low range. Unless you require full gamut or slightly better color quality, or you just like the way it looks. $600 dollars is $100 dollars a year for 6 years. 3 year-ish Warranty, maybe?

Low range + mid range. Dell u2415 or similar $300 = A monitor. 3 Year warranty average. Nice feature set. Same as above DPI/ readability. Close to the same color quality ect as anything 2 times it's price for general pc use, generally speaking. Same glow, same possible bad panel uniformity that you could possibly get from something 2x it's price, or more. $50 a year for 6 years. 3 Year-ish Warranty?

Alas if however 27" isn't too big, or 1440p, and the dpi/text isn't too small ( you'll have to sit farther away or the glow will be bad and the text will be small, plus needing a pc to push it) there are the Viewsonics VP2770, the Necs, the BenQ's, Color/prosumer oriented $600 dollar range monitors that you can fill in that mid range with. All very similar.

But. If a $1200 dollar Eizo is out of your range, and $600 dollars is too much for too little, and or you would be ok with 1080P 24" or 27", there are a plethora to choose from, all basically similar with a different stand /design. Throw a dart at one, or pick one that's pretty. Or that has buttons where you like them. Or is flicker free ect. Read a few reviews, take it with a grain of salt, know what to expect, expect the worst, and maybe your sample will be a little better than the reviewers if you're lucky.

And for our final featurette.

"Old" backlit vs "New" edge lit, as performed by a sheet of paper and a led light.


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Thanks, yes, that makes sense. It might be that CCFL backlight is much more uniform by default than those new edge-lit LEDs, which means that I won't have a chance to find anything good in foreseeable future, while CCFL is gone and IOLED is not quite there for PC monitors.

Another problem is that sometimes more expensive monitor has crappy bacllight compared to some cheaper model. In my case my old cheaper Viewsonic with 6 bit e-IPS panel has smooth solid color, but the brand new Asus ProArt (costed me almost two times more) which Asus advertises as Professional with 8 bit colors and some special 10 bit lookup table has the very issue visible in my video.

This makes things really confusing - now I can't rely just on price and "Professional" claims to know for sure that the monitor won't have that annoying issue.

Currently it seems I would like to go with 1080P 27" - I don't need higher resolution anyway because the text would be too tiny for my vision. I might consider a professional model from Eizo, if only I had a chance to see it in person before I buy.

I guess, the best I can do now is to annoy authors of reviews and owners of IPS monitors with requests to shoot a video similar to mine, so I can evaluate backlight unfiromity on solid colors. :) At least thus I could immediately filter out some worst models.
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