This article stands as a shining example of technical writing at it's finest - you investigate the questions people want to know answers to, your methods are clear, and you write with clear, excellent, English!

would be nice for a list of monitors that include the new lighting system

This is an article that most other sites can only aspire to -- Very Well Done!

> The rods have excellent sensitivity but make no difference
> between wavelengths.

That isn't actually true. Rods are more sensitive in the blue than they are at other wavelengths. The maximum sensitivity of the eye in bright light is at about 550nm (in the green) but in dim light it's around 500nm.

This is why the light used by a stage manager or a prompter in a theatre is blue: the stage manager is in dim light, but the light on the stage is bright enough for the audience's eyes to be in bright-light mode. The stage manager can therefore make a blue light bright enough to read by without it becoming visible to the audience.

This is also the reason why the lights in a submarine are traditionally red when the periscope is in use. The lighting inside the submarine will be bright enough for the submarine crew's eyes to be in bright-light mode, but the eyes of sailors on a surface ship at night will be in dim light mode. This means that the surrace people are less likely to see red light coming up through the periscope than would be the case for white or blue light, but the people inside the submarine still have enough light to see by.

Terrific and very thorough article, Oleg. Now I understand something that previously seemed anomalous with my own LCD monitor. After running it for quite some time at the 75Hz refresh rate (the highest rate seemed the natural choice), I happened to try 60Hz. I was surprised that in some circumstances the motion seemed a little smoother, though barely perceptible. I settled on that as my preferred setting, and only now do I realize it's because the monitor had been dropping every 5th frame delivered by the video card running at the higher setting. That seems like a very strange engineering choice.

Thanks again for such a well-written article.

Great article about LCD vs. CRT monitors. I learned a lot.

Thanks Oleg for this great article. It's writing like this article and your PSU write-ups that makes X-bit labs the best PC hardware enthusiast site on the Internet (at least in English--that's all I can comment on!)

I even managed to learn a new word, "etalon", although I'm still a bit unsure of its meaning. ;)

After reading the discussion in this comments section regarding A/V sync perception, I'll have to do some tests of my own using a tool like Visual Quality Studio ( http://visumalchemia.com/vqstudio/ ) and a couple video clips made in such a way that the opening and closing audio/video frames don't unfairly reveal which clip is which!

Excellent article.

I do agree with some of the criticisms of various perceptual issues regarding lag, et al.. The issue of course comes down to the individual.

As an example (having no better common reference at hand) of FPS style games, there are often game that have options to turn on and off triple buffering as some people feel this gives an effect of 'floating' where the game is not quite responsive.

A game engine, combined with an LCD, human response time and everything else may or may not make the difference between what is and is not perceptible.

To further that point, the issue of audio vs. video timing, human perception is adapted to accept sound lagging image. Using the example of a pile-driver in the distance, you see the driver make contact far before you hear the sound.

To reverse this is an 'unnatural' situation, hearing the pile-driver make a sound before seeing the action would cause 'discomfort.'

But again, it is what is and is not perceptible. Various people have different levels of visual and temporal acuity. Some people, familar with NTSC television at 60 fields per second find PAL television at 50fps to be 'flickery.' The difference is minor but a small percentage can tell the difference.

Again, an excellent article. I'll have to come to this site more often!
G

"Cutting it short, the problem does exist theoretically, but its practical effect is greatly overstated. An absolute majority of people won’t ever notice a lag of 47 milliseconds, let alone smaller lags, anywhere."

No, no, and no.

You've got two pages of pyschobabble on why input lag shouldn't matter, which then transition to an inexplicable contempt for your audience. UFOs? Suggestion? Are you joking?

I moved from a CRT to a Dell 2407. Excellent LCD, this. But it completely ruined any kind of high-level FPS play for me. I used to ridiculously good at Halo, but not anymore. I don't even play it. I can see, obviously, the lag both in Halo on simply moving the cursor across my desktop. It's nothing like having a high ping, and it's nearly impossible to compensate for.

I submit, this monitor may have more than 47 ms of lag. Or it may not. Either way, while your technical explanations have merit, this article immediately drops 15 rungs on the credibility scale when you start attempting to probe the psyches of your readers.

"...the picture looks like soap operas with their unnaturally smooth movements."

I know what you mean, that we are accustomed to 24 fps motion to mean film origination and presumably high quality. But still, for most people with normal vision, the real world is smooth. It is that 24 fps flicker that is "unnatural."

Thank you for an excellent article!

I would comment on 60fps/75fps frame-skip concern (page 5), which seem not to be purely correct from the technical point of view.

1. Vast majority of LCD monitors are physically not able to implement any frame-skipping.

2. What is usually seen when a frame-skip occurs - is a implementation of particular video player, playing 60fps content on a 75fps output rate.

The effect described is most probably related to video player, not the monitor. I do believe standard PC playing some video file was chosen as a video source for the monitor, not any special video testing generator equipment or specialized PC software.

Here's the technical background.

None of the mass-market PC LCD monitors has frame-buffers in their controllers. To implement the feature you described (frame-skip is a most simplified version of "frame rate correction") a monitor controller should capture incoming video at 75Hz and display it at 60Hz by means of using a frame-buffer to store incoming frames and displaying them from a frame queue..

Since monitor controllers normally (I do not want to use word "almost", but it seem to be the case :) have no such frame-buffers, they are physically not able to do any frame-skipping. Monitor displays everything it is driven with, at the rate it supports.

Correct testing of video smoothness would include use of special testing equipment or specially designed software which moves some object exactly with a refresh rate of monitor I do beleive such software could be easily googled. At least some D3D or DDraw example source codes which could be compiled into simple testing software.

It is required to assure that picture is changed honestly 75 times a second with an equal displacement from frame to frame at the SOURCE (PC or testing equipment). Then, it will be correct to issue any tests on destination (monitor output).

Yet another technical details on "why not to use video players" for motion smoothness tests.

When using any video player with a predefined content (usually same 24/30/60fps source video file for testing on 60fps and 75fps) the player willl simply align the input and output frame rates by skipping or duplicating frames (duplicating in most cases actually). 60fps optimized content will have non-smooth playback on a 75 refresh rate system (actually it will be frame duplicating, not frame-skipping). That is what usually seen as a non-smooth video playback.

Thank you again for an excellent review! Hope that my comment will be helpful.

I wish there was a test comparison of the current 24 inch and 30 inch monitors. I have no interest in gaming ability as my use would be strictly for color photo, prepress.

Great info, but someone not having the experience will have problems in applying this information in chosing a LCD.

Great article indeed, but I still have to call BS on those input lag statements. I've gone from 245T to 275T off to L245WP, and finally to LP3065.

The two Samsungs I returned the very next day, due to not being able to even operate in desktop environment, let alone play any games. The lag on 245T is so ridiculously apparent, that if you can't feel it get help. You've some serious neurological issues.

The LG was the very first LCD I was somewhat comfortable with using a mouse. And finally moving up to the 30", and yet being completely satisfied with it, in both gaming and desktop use, I completely disagree with the "increased horizontal resolution" as an explanation why some people "imagine they feel lag"

In between L245WP and LP3065, I went back to my old trusty CPD-G520 for cpl of months. After getting the glorious HP 30" on my desk, I felt no lag...

[Unfortunately, many uses don’t follow even these simple recommendations. This leads to multi-page forum threads like “Help me find a monitor that wouldn’t strain my eyes”.]

Your 'research' is only based by your own experience, which makes you are the one who go absurd. Because you don't survey other people.

Not everyone irritated by LCD fluorescent light but that doesn't mean it is not exist. Like me, I'm comfortable with CRT monitors in many kind of environment (except in darkness), but I felt slight headache and eye strain with LCD, no matter brightness, contrast, and color theme I use.

Sure we don't know what really happens but the symptoms exist. I found some suggestions that can reduce my problems here:
http://www.cloanto.com/users/mcb/19960719lcd.html

http://www.msnbc.msn.com/id/24934303/

That's right. All of us who imagine we feel the lag, are clearly delusional... :D