[Kamares]

As a further comment – the viewsonic was too bright so ran at 40%. Running at 100% to check PWM effect did not help because I could not look at it that way either …

[PCM2]

@ thesharing

The new 11T models have a different P/N (printed on the label on the back of the monitor) – see this thread or the review. Have you tried your ASUS monitor using LightBoost? You should also see 144Hz listed as a useable resolution straight off on your ASUS – it’s the same with BenQ. If you are going to be using LightBoost then there is no use for a ‘flicker free’ backlight as the two can’t be combined. As explained in this article making the backlight strobe as LightBoost does introduces its own form of ‘flicker’ but it’s different in nature to PWM. If this troubles you on the ASUS it won’t be different in nature (the flickering) on the BenQ models. I’d recommend sticking to 144Hz or 120Hz without LightBoost if you do get the BenQ for optimal visual comfort without any flicker.

@ Kamares

Thanks for posting your problem here, it’s always nice to have these sorts of contributions to the forum and have things answered publically so others in the ‘community’ can benefit. It won’t have anything to do with the panel type (IPS) but there are several differences with the ViewSonic LCDs that could be bugging you. As noted in this article on responsiveness CRTs and LCDs ‘sample’ differently and therefore the refresh rate has a different effect on the image. Specifically typical LCDs like the ViewSonics are not constantly refreshing and use a ‘sample and hold’ approaching – so unlike CRTs there isn’t any ‘flicker’ tied specifically to their refresh rate. As mentioned earlier in this thread some users are sensitive to motion blur and can get a feeling of ‘nausea’ when viewing motion on 60Hz LCDs. Do you feel your symptoms coming on more when watching moving objects on the LCD (could be when scrolling a lot on a web page, moving a window about or playing a game) or could you be reading static text and having the same feelings?

[thesharing]

Thank you PCM2,

The LightBoost was only a question, i think i’ll never use it.

So, do you think that BenQ XL2411T have better, worse or same color quality than this monitor? It’s not pretty clear in the comparison.

Also, how can I be sure that i’m going to buy the reviewed, flicker-free version and not the old one?
Can you link me a trusted one? I’m from Italy, EU.

Does standards still differ or i can buy an american monitor without problems?

Thank you

[sbaragnaus]

Hi thesharing, I’m from Italy too. Flicker free product number for Benq XL2411T is 9H.L9SLB.DBE.

[Tone]

I found the comparison very clear. If you look at the colour quality section and the comments in the conclusion it is clear that things go in the Benq’s favour. That comparison and the reviews really helped me make my mind up. Got a flicker free XL2411T from Amazon back in Nov and have no probs with it. Yeh colour is not great out of the box but using the guidance in the reviews you can make it look nice. I too am sensitive to brightness and flicker but don’t have issues with this Benq.

Keep up the great work guys and happy near year!

[thesharing]

Hi again,

In that shop, i see also BenQ Xl2420T is flicker free and with the same presentations, it just cost a little more.

Can somebody tell me the differences between them?

[PCM2]

Glad you found the comparison helpful, Tone, and are happy with your BenQ.

Can I make everyone aware of this post? Please don’t link to or discuss other retailers. Amazon sells a lot of these for a good price and likely have a better returns policy. Because they sell many they are likely onto the newer ‘flicker free’ stock by now – since only the flicker-free model has been in production for several months now. Also note that ‘QBE’ signifies the old model that is not flicker free. But most retailers won’t update their product descriptions or codes to reflect the new stock anyway.

The XL2420T is also now flicker free in Europe – there is a huge thread comparing the two. Note that this initially focused on the old models. The XL2420T now also has a 144Hz refresh rate and flicker free backlight. So the aesthetics, ports, price and some of the features are key differences.

[thesharing]

According to the two tech datasheet, seems all perfect identical except of size.

I linked that site for tech datasheet, sorry for this.

XL2420 also have 6-bit color? seems yes.

I don’t understand the price difference.

Here, it’s reviewed as 2ms response time, but some website mark it as 1ms, what’s right so?

PS: I must wait until 3 january for send this monitor back, so we have time to think better about what to buy

[Kamares]

Hi PCM2

Thanks for your quick reply ..

I connected one of the Viewsonics to set up and initially it was much too bright. I spent 3 hours
playing with the settings after which I felt ill. During that time I did not run any fast moving games
or similar. I was looking at static pdf’s to judge the brightness and contrast levels and browsing the
web to find any sites that had relevance to the way I felt. (That’s how I found this site). During
browsing, I was scrolling up and down articles as I found them. I gave up after 3 hours. Tried again
the next day for a couple of hours (with the second Viewsonic – no change) and again the 3rd day for a couple of hours before I was finally convinced it was the monitor and surrendered. At that point I took them to my local Computer shop on Xmas eve and sold them. Then back to my CRT. Even now, 3 days on, my eyes feel as if they have been blasted and are sore. My headache has finally gone. So, I guess the answer to your question is that I was not aware of blur with the mouse but didn’t play fast moving games so don’t know how that would have worked. I was reading static text and doing a lot of slowish scrolling.

Picking up on something in the threads / TFT central – I was also having trouble in focusing with the
Viewsonics and had to keep looking away to let my eyes settle.

I read the links you gave me and understand, I think, that:

– IPS is probably not an issue.
– You didn’t mention blue reduction so I guess that’s not an issue.
– Sample and Hold / sampling method / PWM probably is. (Question = Do I understand that Strobe backlight is the same thing as PWM free ?)
– MPRT / MMCR are relevant.

– Not clear about frequency. Whilst I get that frequency / refresh is not the same thing CRT / LCD,
there seems to be a correlation between refresh and perceived flicker that is still relevant ?? If so, then 60Hz is out for me because I do get the nausea as you say some people do. That means the BL 912 4:3 is out of the frame.

Then, Motion Blur Reduction.

You say the upcoming XL2411Z and XL2420Z have Motion Blur Reduction and blue level adjustment – which seem to be an upgrade. I see them in the US site Benq.com but not in the UK one – Benq.co.uk. Do you have any idea of release dates?

So, going back to my actual issues, does all this help to guess at what may be the things that I should consider, and which monitors I can select from ? I can wait for the XL2411Z / XL2420Z if necessary, I guess .. If, of course, the Motion Blur Reduction is worth waiting for ..

I may be buying more than I need, but after the Viewsonics, I prefer to overkill it rather than buy something that gives me grief again ..

I note also that Benq is not the only possibility. You have mentioned Eizo and Acer elsewhere …

I still prefer to think about a 4:3 screen but could live with 16:10 as long as I can set it to 4:3 – but the 60Hz worries me.

I do appreciate your time in reading this. It’s a pleasure to find a source that really understands such issues – and over the holiday season too … Many thanks ..

Kamares

[Kamares]

Hi PCM2 -again,

Just went to a friends house. He is running a very old LCD monitor. Seems it does not pull at my eyes like the Viewsonics …

Maybe there is a clue here somewhere ..

His monitor is as below:

HYUNDAI N71S Black 17″ 5ms LCD Monitor 280 cd/m2 800:1 Built-in Speakers

HYUNDAI Model N71S
Display Screen Size 17″
Widescreen No
Maximum Resolution 1280 x 1024
Recommended Resolution 1280 x 1024
Viewing Angle 150°(H) / 130°(V)
Pixel Pitch 0.264mm
Display Colors 16.2 Million
Brightness 280 cd/m2
Contrast Ratio 800:1
Response Time 5ms
Horizontal Refresh Rate 30kHz – 80kHz
Vertical Refresh Rate 60Hz – 75Hz
Panel A-Si TFT Active Matrix
Display Type SXGA
Connectivity Input Video Compatibility Analog RGB
Regulatory Approvals
TCO ’03, FCC, CE, CB, VCCI, UL/CUL, CCC, PSE, GOST,TUV-GS

Thanks again,

Kamares

[PCM2]

@ thesharing

The XL2420T used to use a 120Hz panel with a 2ms grey to grey response time and relatively poorly implemented overdrive (this ‘AMA’ thing). This ‘old version’ is what we reviewed. BenQ now use exactly the same panel for the XL2411T and XL2420T – it’s a 144Hz one with a 1ms grey to grey response time and better balanced AMA (has three settings instead of two and the middle one called ‘High’ is quite good). Like all 144Hz monitors it is 6-bit + FRC (dithering). In fact all non VA panel models in this price bracket are 6-bit + FRC. It will make no difference at all for your uses and isn’t something to worry about :). I still think the 11T is the better choice for you if you don’t care about the looks or extra ports on the 20T. That is why it costs more, not because it uses a better panel.

@ Kamares

Thanks for your thorough analysis, this really does help me to get closer to pinpointing the issue. Refresh rate is only linked to ‘flicker’ if the display is impulse driven rather than sample and hold – so LCDs using a strobe backlight mode, for example. This is because the strobe frequency is generally synchronised with the refresh rate – so it’s very CRT-like behaviour. Normal LCDs have a backlight which will only ‘flicker’ if it uses PWM to modulate brightness. With a normal sample and hold LCD that is PWM free there is no flicker regardless of refresh rate – and refresh rate simply affects the smoothness of motion or level of motion blur in the way the article describes. If a strobe backlight is used then the strobe length (i.e. how long the monitor is in its ‘bright’ phase) determines the brightness output. PWM regulation is never used alongside a strobe backlight because they would interefere with each other, but due to this very nature you can’t say a strobe backlight is ‘flicker free’.

Given that you were able to use what is an old and relatively sluggish (by modern standards) Hyundai display with no visual discomfort that really helps rule out anything motion blur related. I am quite inclined to believe that you are sensitive to Pulse Width Modulation which wouldn’t be used in the same way on the Hyundai model as it is CCFL-backlit. I wouldn’t worry about blue light levels, they can be moderated easily on most modern LED-backlit models by altering colour channels. I like the dedicated ‘Low Blue Light’ modes on some of BenQ’s new screens (like the EW2740L) simply because I like to switch to that sort of mode easily in the evening. You can use a utility called ‘F.lux’ which essentially does the same thing automatically. The ‘Blue Light Modes’ were particularly impressive because of how strong the contrast was when using them on the EW model – F.lux or big colour channel adjustments will reduce contrast on most displays. This is really of less importance than your overall visual comfort, of course.

As for the XL2411Z/XL2420Z I don’t have any further information on their release dates but will update the article as soon as that is known. The 27″ XL2720Z is due to be released in the UK and Europe in January and I expect to see the 24″ models follow shortly afterwards. I think you might be better off sticking to a monitor with just a PWM-free backlight rather than a strobe backlight, though, especially as you don’t seem overly sensitive to motion blur. Or at least that doesn’t seem to be contributing to your eyestrain. If you were happy with a ~24″ monitor then it might be worth waiting for the EW2440L instead which will feature a flicker-free backlight and ‘Low Blue Light’ modes as well as a VA panel with a light matte screen surface. It basically does everything right for ‘reducing eyestrain’ if it isn’t caused by motion blur sensitivity.

[Kamares]

Hi PCM2,

I see the EW2440L is on sale in Canada for $ Can 299 (UK £ 169). I was prepared to pay more than that if necessary and seems like a good deal. There is one seller on EBAY that will sell to UK for about that price plus import duties and shipping, so, it is almost available now …

I note that it does not have screen scaling but rather the ability to dim the sides of the screen. As long as it is truly dim, then OK for my needs – mostly writing, reading word docx / pdfs and browsing. Hard to tell how dim the sides will be though ..

It does have a lot of abilities that I don’t need but I can just ignore them – although the cinema mode might be worth experimenting with.

No mention of refresh rate on the Benq site though. However, I note from your words that refresh rate is linked to only strobe backlighting – which this does not have, but it uses, I assume, Sample and Hold, which is what I thought the problem could have been in the first place.

1 – I assume this runs at 60 Hz – Yes / No ??

So, Sample and Hold OK then (based on my own comments ..) because it would appear that motion blur as such is not a main part of the problem. The Hyundai I looked at is running at 75 Hz but I put it on 60 Hz for 10 minutes and, reading pdf pages, seemed OK. Much too bright for me though but didn’t want to mess up his settings by changing … (He is running a totally stand-alone system not connected to anything else for security and keeps all his confidential docs on it. It’s also still on Win 98 which is fine for that …)

As an aside, my eyes are still sensitive – even after several days, so I am only using the CRT for short periods at the moment because the brightness still bothers me – although it is still set to what it was before all this started. (Changing doesn’t help, so I am waiting for my eyes to settle again). It is getting better though. I should maybe be the subject of some weird study …

And, to fill in another part of the puzzle – in case anyone wonders – I wear glasses and I had my eyes tested 4 weeks ago as a regular yearly check-up. I am OK.

2 – I am surprised that it does not have DVI-I. Seems like a back step ?? My GTX card has HDMI and VGA and also DVI-I which I have always assumed would be better. – Yes/No ??

3 – In any event, I can use either straight VGA or a VGA to HDMI cable / connector on the EW2440L, I assume. Is there any advantage either way – Yes / No ??

I have separate speakers so audio not an issue. And, I have audio turned off most of the time anyway – except for SKYPE calls.

You have not touched on the 912 4:3 model and since that does not have as many eye care features I guess I will give it a miss…

So, OK, I will wait for this EW2440L and risk it. I will not really know until I try but very much appreciate your help in figuring out the most likely cause of my problems. I would like to think that someone from Benq or other might read all this and get something out of it. (Still cautious about refresh rate but we shall see …..)

I do wonder, also, why this new / latest model does not say that it covers 120 / 140 Hz since that is where gamers will go ??

You know, I cannot help observing that, as far as I can see, CRTs are still better than LEDs in every respect. If there were still a decent CRT manufacturer then I would not have even bothered with LCD / LED at all. (Same with tvs. Just bought a Panasonic plasma to get a half decent picture.) Or am I being too controversial here … What do you think ?????

Appreciate your comments on my above questions…, and then, for the moment, will wait for the UK release.

Regards,

Kamares.

[PCM2]

It’s good that you can source the EW2440L! I’ll address your questions directly:

1) Yes it is 60Hz – you should always assume a modern monitor is 60Hz unless otherwise stated. Almost all are now 60Hz with the exception of models that are 120Hz+ and the manufacturers will make sure you know if that’s the case. I’ve added the fact they are 60Hz monitors to the article for clarification. All current 144Hz gaming monitors (and with the exception of the Eizo FG2421 all 120Hz ones) use Twisted Nematic panels. VA panels such as the EW2440L offer considerable contrast and colour reproduction benefits. 120Hz+ refresh rates are generally a compromise and not all gamers are prepared to go there. You can actually overclock the EW2740L (and probably EW2440L as well) to 72Hz+ very easily by setting a custom resolution in Nvidia control panel.

Because the EW2440L, like most LCDs, is sample and hold, this has no effect on the backlight behaviour and from your visual comfort point of view shouldn’t matter. It’s good to hear that your eyes are fine, I’m sure that must be of comfort given the extent of the discomfort you’ve been feeling on the ViewSonic monitor.

2) HDMI is a smaller port and has simpler (less bulky) internal electronics. It’s also universal and works not just with PCs but also games consoles. And you can fit multiple HDMI ports in place of one DVI port. For these reasons manufacturers will often use only HDMI (and sometimes DisplayPort in addition) rather than DVI, particularly if they’re going for a thin and stylish monitor. In this case there is a VGA port which you could say the same about! In that sense BenQ have made a strange decision as noted in the review. Some additional steps will need to be taken to ensure your Nvidia GTX GPU uses the corect colour signal over HDMI. Exactly the same steps as those shown in the calibration section (‘Correcting the HDMI colour signal) of the EW2740L review.

3) You’d want to use a straight HDMI cable or DVI to HDMI. If you use the VGA output of your graphics card (or the monitor) you’re restricting yourself to an analogue signal. That is OK but you do get slight quality degradation compared to the digital signals.

This isn’t really a discussion I want to take on here, but I think it’s easy to look at CRTs using rose tinted glasses. There was plenty to like about them but many modern LCDs offer obvious advantages and personally I was happy to see the back of CRTs. For many users they were not at all comfortable visually, lacking the sharpness, matte surfaces and ‘geometric perfection’ of LCDs. The poor screen size and relative bulky and unwieldy nature was also a barrier for many people. ‘Real world’ contrast is also far better on modern LCDs with VA panels in particular because lighter colours on CRTs glow intensely and lighten the dark and black areas considerably. Now plasma is a different issue but that is not a monitor technology due to the restrictions on pixel size. The pixels are gas filled chambers and can’t be made small enough to give good resolutions on small screens because the pressures would be too great. OLED is where things are headed and that will give better than plasma performance for monitors but for now modern flicker-free LCDs like the EW2440L can provide a very comfortable viewing experience which many people would actually prefer to what CRTs provided.

[Kamares]

Hi PCM2

Thanks for that.

I am re-reading all the links and articles to get a complete understanding of all this …

Re. CRTs – OK, point taken … I have only used CRTs and this is my first venture into LED tech. Mainly because the CRTs just kept running – until now, that is. They are both giving problems and probably won’t last much longer.

Thanks for your help …

In the meantime, when I have digested all the threads and links, may I bother you again for clarification on the tech .. some of it needs reading twice …

Thanks again,

Kamares

[thesharing]

Hi PCM2

Finally i sent back the ASUS monitor, and today i went to Amazon for the XL2411T:

But, one review (Dec 2013) say it’s not flicker-free… who is right?

I saw also that the “benq xl2720z” is going to be released this month, is it true? what do you suggest?

[PCM2]

Hi again,

As noted in our review the old revision of the XL2411T (which has the P/N: 9H.L9SLB.QBE) was not flicker-free. The new revision (which has the P/N 9H.L9SLB.DBE) is flicker-free. The person who reviewed the monitor in December 2013 must have received an old revision. Here in the UK you’re pretty much guaranteed one of the new models if you buy from a major retailer who shifts a lot of stock (like Amazon.co.uk). Amazon.it must have had some mixed stock. At least with them it’s very easy to return the monitor if it doesn’t meet your expectations (i.e. it’s the old revision that uses PWM).

We have some information on the BenQ XL2720Z and other members of their Z series on this news article which is currently at the top of our homepage in fact. It has the latest information on these monitors and the latest information about their projected availability. If you’re purely interested in a flicker-free experience then there is probably no reason to wait for the more expensive XL2720Z (or even, more appropriately, the XL2411Z). Then again you might quite fancy those ‘low blue light’ modes or find the ‘motion blur reduction’ strobe mode comfortable to look at – it still flickers, but the nature of that flickering is not the same as PWM. Some people who are quite bothered by PWM flickering find strobe modes quite tolerable. A full review of these monitors, time permitting, would obviously reveal the finer details.

P.S. If you’re buying anything from Amazon be sure to use our links (bottom of the XL2411T review for example).

[thesharing]

I think, BTW, that return a monitor for the 2nd time is not so good idea, so i will look for some online Italian shops, and I found that it’s also cheaper than Amazon (30-50€ difference).

I’m pretty courious about the XL2720Z about the blue light and motion blur reduction, and also about the panel that they’re going to use (maybe, better colors?)

BTW If you don’t have a release date i think i will take the 11T, from one of those shops.

In waiting, there is a color/settings calibration set for the Rev.2 version of the 11T ?

[BrianC]

I went ahead and bought three of the Benq XL2411T monitors (I am located in Canada and got them from Tiger Direct) and am extremely pleased with them. Thank you so much for your recommendation.

[PCM2]

@ thesharing

Amazon Italy’s price on that monitor is a bit high. Hopefully the shops have a decent returns policy, though, or can guarantee that it will be the new revision. The setup is much the same as on the old revision 11T. You might want to try ‘Gamma4’ as well as ‘Gamma5’ and see which you prefer.

@ BrianC

Great to hear! I hope you continue to enjoy the monitor. 🙂

[thesharing]

Yes, shop have both: 14 days return policy and specified product ID on the page, if i wish a good IPS for films/quality color production, what do you suggest?

[Author]

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