High Definition 3D: 120Hz Monitors from Acer and LG

We are going to talk about two first and, actually, the only 3D monitors with 1920x1080 resolution that are currently available to general public. Please welcome Acer GD245HQ and LG Flatron W2363D.

by Oleg Artamonov
11/23/2010 | 12:35 AM

Nvidia’s stereoscopic vision technology, 3D Vision, came out quite a long time ago, but monitor manufacturers do not seem to be in a hurry to implement it in their products. I guess this market sector is just not hot enough yet. And instead of trying to heat it up by their own efforts, the manufacturers prefer to wait for the mass arrival of appropriate consumer electronics and content, i.e. 3D TV-sets, 3D players and 3D movies, which would promote consumers’ interest towards stereoscopic content in computer games.

 

This situation presents a number of obstacles for users who want to enjoy true 3D gaming right now. One of these obstacles is the limited number of 3D monitors available today. Moreover, while the resolution of 1920x1080 has already become standard in high-quality home monitors, early 3D Vision-compatible models only had a screen size of 22 inches and a native resolution of 1680x1050 pixels.

Fortunately, things have improved over time and I can now share with you the results of my testing two 3D monitors that have a resolution of 1920x1080 and screen sizes of 23.6 and 23.0 inches.

Acer GD245HQ

Acer was the first manufacturer to produce a 120Hz monitor with a native resolution of 1920x1080, about half a year after the release of 20-inch 120Hz models (1680x1050).

Exterior Design and Ergonomics

 

These days it is hard to impress a consumer with black gloss and original shapes. There are rows of such monitors standing in each computer shop. Acer designers have managed to stand out among the crowd with very simple means: the three rich-orange faceplates on the monitor's stand contrast with the black case to catch the customer's eye. Coupled with the angular shapes, these orange spots make the monitor look somewhat aggressive, which is just what you need in a gaming model!

By the way, the monitor’s screen is matte, and I think that’s good. Glossy screens may look splendid on a shop shelf but produce too much glares under real-life conditions.

The rear view is very standard. We’ve got plain black matte plastic here. You can note the mounting holes for VESA-compatible mounts. They can be used to hang this monitor on a wall or just replace its default stand with a more functional one.

 

The default stand’s functionality is limited to changing the tilt of the screen. No height adjustment and no portrait mode here.

 

The Acer GD245HQ is equipped with a full selection of inputs: DVI, HDMI and D-Sub. The last two interfaces are going to be useless if you want to enable 3D mode. They do not support display modes higher than 1920x1080@60Hz whereas the stereoscopic vision technology needs a refresh rate of 120 Hz.

Although the HDMI interface (in version 1.3 and higher) supports frequencies up to 340 MHz, HDMI receiver chips used to be limited to 165 MHz, i.e. to 1920x1200@60Hz. It is only recently that 225MHz chips have begun to be used. Easy to calculate, this frequency is still not high enough. The 1920x1080@120Hz mode needs an HDMI receiver with a frequency of over 250 MHz.

3D-enabled TV-sets solve this problem by using interlacing (1080i60 mode) or lowering the frame rate by half (1080p30). Both solutions help fit two video streams, for the right and left eyes, into the 165MHz bandwidth, but computer monitors do not support them.

Thus, the DVI interface is the only option to enable 3D mode on the Acer GD245HQ. There is only one requirement: you need dual-link DVI, but every modern graphics card offers it. It is only when purchasing a DVI cable (if the included one doesn't suit you for some reason) that you should make sure it supports dual-link DVI. Cheap single-link DVI cables are rare but still available.

The single benefit of HDMI in the Acer GD245HQ is that you can connect this monitor to two video sources simultaneously, one of which will be able to work in 3D mode.

There is a green audio connector to the left of the stand. It outputs the audio received via HDMI. The monitor doesn't have an analog audio input.

The monitor’s controls can be found on the right of the bottom edge of the case. They are not labeled on the face panel. There are only small dots there indicating the position of the buttons. I guess this solution would be appropriate if the functions of the buttons could be redefined, but here the lack of labels is somewhat inconvenient.

Onscreen Menu and Setup Options

The Acer GD245HQ offers the same settings as many other modern inexpensive TN-based monitors.

Pressing any button opens up an introductory menu with the following items:

The Empowering Technology menu offers four preset modes besides Standard in which the image-enhancing technologies are all turned off. Three of these modes are not editable and the fourth one is user-defined.

The image enhancements are achieved by increasing color saturation, contrast and sharpness for games and movies. People who prefer natural-looking colors won’t like this Empowering Technology, I guess.

The main menu is ordinary, too. The first screen allows you to adjust Brightness, Contrast and Color Temperature and to access the abovementioned image enhancement modes. Most of the items are not available as they refer to the analog connection only.

 

The second screen contains but one setting that pertains to the onscreen menu itself.

The monitor’s technical settings can be found in the third screen. You can choose an interpolation mode here: full screen, with restrained proportions or pixel-per-pixel. The Adaptive Contrast Management (ACM) option enables dynamic contrast technology.

The last menu screen offers some information about the monitor: serial number and operation mode.

First Impressions

Alas, my very first impressions from the Acer GD245HQ proved to be rather unpleasant. The monitor has a serious problem with sharpness. Take a look at the photo:

The fonts look normal on the right, but the exceedingly high sharpness adds a bright outline to the letters on the left. Moreover, this picture is not a combination of two photos. It is one photo. The separating line between the normal and “highlighted” parts of the image goes from top to bottom exactly along the middle of the screen.

After some experimenting the following solution was found: you can eliminate that effect by disabling response time compensation (the OD option) in the monitor's service menu.

To enter the service menu you must turn the monitor off and then turn it back on while keeping the left button pressed.

Alas, this is hardly a good solution. The response time compensation is turned off completely, so the monitor becomes an ordinary 5ms model even in 3D mode, which is too slow to keep up with the 3D glasses. In other words, you have to turn the response time compensation back on to play in stereoscopic mode. Besides, when the OD option is disabled, the monitor automatically enables dynamic contrast after being turned on.

There is a way to eliminate the excessive sharpness without turning off the response time compensation option. You go into the service menu, turn the OD option off, choose Reset, then enable OD again, and press Reset. This keeps response time compensation enabled and eliminates the excessive sharpness but only until the monitor is reset (i.e. until the next time you turn it off and on). That's not handy, either.

These somewhat crazy relationships between different settings make it clear that the monitor’s firmware is written in a sloppy manner and is full of various bugs. The response time compensation should not be related to the display of a static image or to dynamic contrast, but it is related to both, and in a poor way, in the Acer GD245HQ.

I checked out two different samples of the monitor manufactured half a year apart: one in the spring of 2010 and another at the end of the summer. There was no difference. Both had the above-described defect. Acer seems to be in no hurry to correct such an unpleasant problem.

Summing this up, I should say that if you care about the monitor’s ability to display text normally and deliver good image quality in 2D applications, you should be very careful and check the GD245HQ out in this respect before purchasing it.

Brightness and Contrast

The monitor's Brightness and Contrast settings are set at 77% and 50%, respectively, by default. I achieved the reference 100-nit level of white by choosing 30% Brightness and 44% Contrast. The monitor controls its brightness by means of pulse-width modulation of the power of the backlight lamps at a frequency of 238 Hz. It is always set at the maximum in 3D mode so that the flickering of the lamps didn’t combine with the switching of the 3D glasses’ lenses.

 

The monitor has typical brightness and contrast ratio parameters as today's products go. I would only wish the maximum brightness were as high as 300-350 nits. 3D glasses absorb quite a lot of light, so the screen looks darker in them than when you look at it in 2D mode without the glasses. 3D monitors do need some more brightness than ordinary models.

 

The screen brightness varies from 134 to 250 nits in the preset Empowering Technology modes. It must be noted that 134 nits is rather too high for working in text-based applications even under bright office lighting. In a home environment, you may even want to lower the screen brightness to 70-80 nits to avoid staining your eyes.

Backlight Uniformity

The average nonuniformity of black brightness is 5.5% with a maximum deflection of 17.7%. For white brightness, the average and maximum are 6.5% and 15.5%, respectively. These are good results.

Color Accuracy: Gamma, Temperature, Gamut

The monitor has too much contrast at ordinary settings: this is how the eye perceives the too high gamma which is indicated by the sagging color curves in the diagram.

The image only gets worse when you switch into the special Graphics mode: red and green remain intact whereas the blue curve sags even more. The overall effect is that the image becomes warmer and greener. Acer’s engineers believe that such colors look better but I don’t think these image-enhancing technologies will be appreciated by users who prefer natural colors.

The graphs above indicate that the image is too greenish. I corrected this in the User mode by choosing R=94, G=92 and B=100. The result is a color temperature of near 6500 K and a rather accurate gray without any unwanted toning.

These numbers are only correct for my sample of this monitor. Another sample may be set up differently at the factory and will call for different correction. However, if you note your GD245HQ to be somewhat greenish, you may try to set it up as I did in the previous paragraph.

The monitor’s color gamut coincides with the sRGB color space in blues and is larger than it in greens and reds.

Response Time

I usually measure the response time of 120Hz monitors twice, at two different refresh rates. The GD245HQ called for a third test, with the response time compensation technology turned off, due to the defect I've described above.

At a refresh rate of 60 Hz the monitor’s average response time is 3.1 milliseconds (GtG).

The average RTC miss is 7.8% and the monitor takes 13.6 milliseconds to correct it.

At a refresh rate of 120 Hz the monitor's average response time is 3.0 milliseconds (GtG) whereas the errors become far less conspicuous: the average miss is 6.2% and the correction time is 5.5 milliseconds. These numbers are as good as those of other modern 3D monitors. For example, the ViewSonic VX2268wm has a lower response time but a higher level of RTC errors.

Thus, the doubling of the image in stereoscopic mode is just as conspicuous on the GD245HQ as on other 3D monitors such as the Samsung 2233RZ or the abovementioned ViewSonic. You can spot the characteristic artifacts if you know where to look for them, but they are not too gross and do not spoil the fun from 3D gaming.

Users sometimes report a problem about a partial display of stereoscopic content: the top third of the screen shows either an ordinary 2D image or a stereoscopic image with a high level of visual artifacts. I have not spotted this problem with any monitor I have tested including the GD245HQ and I guess this problem depends on the computer rather than on the monitor because owners of different monitor models complain about it.

When the response time compensation is turned off, the GD245HQ slows down, its average responsiveness increasing to 12.9 milliseconds (GtG) with a maximum of 25 milliseconds. It is impossible to use 3D glasses then. The 3D glasses only have some 8 milliseconds between the frames, so in order to deliver an artifacts-free stereoscopic image the monitor must keep the transition between two frames as short as 3-4 milliseconds.

Summary

The Acer GD245HQ would be a good 3D monitor if its firmware flaws didn’t spoil its image quality in 2D mode. There is no simple and reliable solution of that problem and, judging by the lack of improvements (the GD245HQ hasn’t changed in this respect over half a year of mass production) and official reaction from Acer, the manufacturer doesn’t think it to be a serious issue.

To avoid this problem, you should check out the GD245HQ sample you are going to purchase has normal image quality in 2D mode in the left part of the screen.

LG Flatron W2363D

Now I am going to take a look at a 23-inch 3D monitor from LG.

Exterior Design and Ergonomics

Contrary to the Acer GD245HQ with its eye-catching contrasting orange stand, the Flatron W2363D has a trivial and unassuming exterior. It's got an all-black glossy plastic case such as abound in large quantities in every computer shop. If you tear off the Full HD 3D sticker, the monitor won't stand out among other products at all.

The case is all glossy at the back, too. There are VESA mounting holes here for compatible stands.

 

The monitor’s default stand only allows to adjust the tilt of the screen.

You can find a power connector, a DVI input and an analog audio input on the monitor’s back panel.

 

The side panel offers a headphones output (I guess that’s quite a proper location for that connector) and, surprisingly enough, as many as two HDMI inputs. I wouldn't call that a proper place because a stiff and thick HDMI cable is not going to look neat here. On the other hand, you have to connect this monitor via DVI to enable 3D mode, so most users won't utilize these HDMI ports.

The Flatron W2363D has touch-sensitive buttons except for one which is designed as a rotating lever. Oddly enough, this button, being the most conspicuous, performs the least useful function. It selects the operation mode of the decorative highlighting.

There is white highlighting called Tru-Light in the bottom part of the case. It is designed as concentric circles going out of a single center. These circles are going to pulsate beautifully in dynamic movie scenes and at loud sounds but I doubt many users will take note of this feature for more than a couple of times. It has no practical worth and the constant blinking below the screen will eventually get on your nerves.

Onscreen Menu and Setup Options

The menu is designed in LG’s traditional style.

That is, you first have to choose the necessary section of the main menu out of the four available. This only has some meaning for inexperienced users who can see some more information here than just unlabeled menu items.

The first section is where you can specify Brightness and Contrast and choose one of the values of gamma and one of the levels of black. You may only want to increase the level of black to make very dark games brighter. Otherwise, increasing this value will just lower the contrast ratio.

The second section is about color accuracy. You can choose a color temperature mode or set it up manually (by balancing the three basic colors if you use the DVI interface).

You can also use the tone and saturation settings to achieve the desired color reproduction.

The Tracking section contains but one setting, which is Sharpness. As opposed to the Acer GD245HQ, there are no problems with this setting at its default.

 

The Setup section allows you to adjust the headphones volume, enable overscan (for an HDMI connection only), turn off response time compensation, choose the level of the decorative highlighting and disable the power indicator. You can also reset all the settings to their factory defaults.

The small additional menu is for controlling the monitor’s extra features: Thru Mode (eliminates the input lag as I will discuss shortly), SRS WOW (sound processing), interpolation mode, and dynamic contrast mode.

There is another menu for choosing the operation mode of the decorative highlighting. You can open it by pressing the abovementioned lever.

First Impressions

There is not much I can tell you in this section because the Flatron W2363D is neither better nor worse than many other modern gaming LCD monitors. I can’t find fault with its color accuracy, considering that it is a gaming monitor rather than a professional model with an IPS matrix, except that there was slight banding in color gradients and that the image is somewhat cold at the default settings. This monitor doesn't have such sharpness-related problems as the Acer GD245HQ.

Brightness and Contrast

The monitor has 100% Brightness and 70% Contrast by default. I achieved my reference level of 100 nits by choosing 30% Brightness and 42% Contrast. The monitor's brightness is regulated through pulse-width modulation of the backlight at a frequency of 240 Hz.

 

The max brightness is over 350 nits, which is good for a 3D monitor. Nvidia's 3D Vision glasses absorb a large part of the light from the screen, so the monitor should be bright for you to play comfortably in daylight.

Backlight Uniformity

The average nonuniformity of black brightness is 6.6% with a maximum of 22.1%. For white brightness the average and maximum are 5.5% and 16.9%. There is a bright spot in the bottom of the screen on black.

Color Accuracy: Gamma, Temperature, Gamut

At the default settings the monitor has a sagging blue curve but the overall color accuracy is acceptable. Darks and lights are all reproduced correctly.

Lowering the Brightness and Contrast settings raises the blue curve but also makes the darks too bright.

 

The biggest problem with the color accuracy of the W2363D can be seen in the table: its image is too cold in each mode, the color temperature being always higher than 7500 K. The 5400K mode, which should be warm, is actually no different from the 6500K mode. This seems to be a defect of the monitor's firmware. Besides, the white point diagrams show that there is a tonal shift towards green in every mode. It can hardly be visible to an untrained eye, though.

The monitor’s color gamut is roughly the same as the standard sRGB color space.

Response Time

One of the most interesting features of the Flatron W2363D is Thru Mode which is meant to eliminate the input lag (the difference between the moment the frame is received from the graphics card and the moment of its output to the screen). Of course, I checked this feature out to see how it works.

Compared to a monitor that has no input lag, the W2363D has a lag of about 16 milliseconds with Thru Mode off and 0 milliseconds with Thru Mode on. Thus, this feature really works even though I doubt its practical usefulness. It is impossible to spot the 16ms lag with a naked eye. By the way, the lag was the same at a refresh rate of 60 Hz as well as 120 Hz.

Quite unexpectedly, the monitor’s response time is 11.2 milliseconds (GtG) at 60 Hz. There is no trace of response time compensation here.

Switching to 120 Hz doesn’t change the overall picture quantitatively: the response time is 7.2 milliseconds (GtG) but there are still no traces of response time compensation such as RTC misses.

However, if we compare the diagrams and numbers to those of TN-based monitors with no RTC, for example with those of the Acer GD245HQ with the OD option turned off, we can see that the Flatron W2363D is quite fast. This makes me suspect that this monitor has RTC but it is set up in a non-aggressive way. As a result, the W2363D is faster than typical 5ms models but has no RTC-provoked artifacts.

But what about 3D mode when the monitor has to be as fast as 6 milliseconds or better? Unfortunately, my testbed can only work with 2D mode and cannot measure a monitor’s responsiveness in 3D mode. I suspect that the W2363D switches to a more aggressive RTC setup then because the image doubling effect was just as conspicuous with it as with competing monitors. And this effect is determined by the speed of the matrix.

Summary

The LG Flatron W2363D is not an exceptional monitor. Its exterior design is no different from its competitors and its color accuracy is not without drawbacks. The extra features like Thru Mode and Tru-Light are nothing more than trifles to play with on the first day after the purchase.

On the other hand, this monitor is quite a good option for people who want to enjoy stereoscopic imaging at resolutions higher than 1680x1050. It is free from serious defects and delivers good image quality in both 3D and 2D mode.

Conclusion

This review actually covers all widely available 3D monitors with a screen larger than 22 inches and a native resolution of 1920x1080. Other alternatives are either not available in shops or offered in specific regions of the world only.

I should confess that neither model showed anything exceptional in my tests. But while the LG Flatron W2363D is overall just as good as ordinary TN-based gaming monitors in terms of 2D image quality and adds to that with its support for high-definition stereoscopic imaging, the Acer GD245HQ is an utter disappointment with its firmware flaws which result in nasty visual artifacts in 2D mode.

Thus, the LG Flatron W2363D seems preferable of the two if you want an all-purpose monitor. But if you already have a main monitor and want to buy a second one for gaming, the GD245HQ may be a better choice due to its eye-catching design and more flexible settings.

I would also wish that Acer answered users’ requests and corrected the disappointing flaws of the GD245HQ model.