The upcoming release of 120 Hz monitors: afterglow, 3D, etc.

Part 1: The discovery

While minutely picking through the ''key features'' of new Nvidia graphic processors, the GT200s (260 et 280), we came upon this line:

•    Support for future 10-bit colour and 120 Hz LCD panels

1.1 billion colors in output.  Yes, but...

This first item will only interest professionals in video and photography.  The 10 bits refers to the number of gradations per red, green and blue channel. Current cards are 8 bit which means 256 shades of color per component.  The GeForce GTX 260 and 280 have a 10 bit core and they are capable of producing 10 bits (or 1024 levels) per color.  In total this equals a billion shades instead of the usual 16.7 million.  However, there is one large condition:  10 bits seems to be exclusive to the Display Port output, something still rare on graphic cards as it is on monitors.   And at the current time, it appears that DVI and HDMI are content with just an 8 bit output.   If this is indeed the case, it’s rather disappointing.

The real revolution: 120 HZ LCD monitors!!!

''120 Hz'' represents a veritable revolution to come for gamers.  LCD monitors are generally not too appreciated by purist gamers due to:

- reactivity which is inferior to that of CRTs,
- potential input lag,
- and especially, because their speed is limited to 60 images per second.

So the above small line is indication of a real upcoming change that has been much awaited by gamers:  the arrival of 120 Hz screens!  What’s at stake is better fluidity, half the perceived afterglow, action sequences with slightly more detail, and better perception of the surroundings and changes in fast games.

So when and what’s the price? NVIDIA’s white book doesn’t specify and we should be too demanding yet...

Part 2: 120 Hz LCDs = 3D games this summer!

The 3D glasses on sale this summer will be different from these that come with the Zalman monitor.

The confirmation we were missing came yesterday: 120 Hz LCD monitors will be released this year.  We now know a little bit more about the actual dates which, except for any last minute delays, should even mean availability in late June/early July 2008.  And because good news often comes in pairs; there will also be the arrival of 3D glasses that will be relayed to the graphic card (naturally an NVIDIA model).

Put them on and NVIDIA promises 3D immersion as you might have experienced when watching the U2 3D concert movie, considered the best current work of its kind.

We were told new, light and affordable glasses

These glasses are no longer with one blue and one red lens or transparent/opaque.  They are black or at least darker and polarized.  An accompanying 120 Hz screen is indispensable as each eye will actually receive 60 images per second.  The ones viewed by the right eye will be slightly delayed compared to those received by the left.  As for the price, they will be very ''affordable''; however, we do not have any other details.

In terms of the graphic card, older generations will theoretically be compatible.  We say ‘’theoretically’’ because:

- on the one hand, each image is no longer calculated once but twice (or once for each eye).  We could fear that in games which have a fluid rate of 30 images per second this will be cut in half to 15 ips with the same graphic settings.

- on the other hand, it means producing a real 120 Hz with 120 images per second which would be different in current games and with current popular LCD resolutions (22 inches = 1680 x 1050 pixels, 24 inches = 1920 x 1200 pixels).  In actuality, only the most recent and the highest end models will have such a frequency.  We already tried this in the very recent test of the 3D Zalman monitor which produces 3D images with a NVIDIA card in 60 Hz.  It could be even worse in 120 Hz! Theoretically (and even if it wouldn’t function with the Zalman or the technology was different), ''older'' cards could also produce a convincing 3D effect.  Of course, 120 separately processed images wouldn’t be produced per second.  Nevertheless, 120 would indeed be sent to the screen, a good many of which would be a simple duplication of the previous image.  The 3D effect would be there, but fluidity and precision would be inferior to that of the highest performance cards.

Part 3: 120 Hz monitors = 100 Hz TVs? No, not at all.

This assumption was incorrectly made on the forum and needs some explanation.  We said that there will be very interesting advances in games with the upcoming arrival of 120 Hz monitors. EmpereurZorg kindly replied on the forum that there are plenty of 100 and 120 Hz LCDs already on the market integrated to televisions.  This is both true and false.  The Hz of one is not very related to the efficiency of the other.

TVs: every other image is created by the television

With TVs, the source (DVD or Blu-Ray player, tuner, etc.) always sends 50 or 60 images per second depending on your region of the world.  A 100/120 Hz TV will indeed try to display a speed that is twice as high and it will have to do this by interpolation.  A processor is in charge of creating and approximating an intermediate image that will go in between the two received ones.  If the change is simple, it’s just a translation of an object and interpolation functions well.  An intermediate image is added, perceived afterglow is significantly reduced, and the movement on the screen is more fluid and sharper.

Of course, sometimes the process is more complex.  In this case, the processor struggles and fails:

Image 1 recieved

Image 2 recieved

Image 3 : the one displayed

In the above change of shape and color, the processor does not suceed. Not only does it not manage to calculate the intermediate image but it degrades the two original ones.

Part 4: 120 Hz monitor: 120 real images per second

A120 Hz monitor will be relayed to a graphic card capable of actually producing 120 images per second.  There is no longer any interpolation.  We therefore can safely expect to have more precise sequences without error.

However, this will not be without a few negative consequences.  First of all, this will push for the use of ‘’expensive’’ 3D cards to maintain the 120 fps for recent games.  Next, the new found sharpness will accentuate defects in games as well as adding a ''video like'' effect.  Traits will be sharper and probably too much so for those who had problems with a similar transition from CRT to LCDs.  It was something that was judged ''excessive'' in the beginning and some adaption time was required.

This will likely be the case here once again.  It is all the more foreseeable that the 100/120 Hz function of televisions poses exactly the same problem, even on the best current models.  There are those fans who swear by it and others who will not accept it even if they paid a large sum for their TV equipped with this function.

Another question that appeared on the forum was asked by a somewhat “appreciated” regular, Hallucinogen.  In short: what enables us to assume that doubling the frequency will have any influence on afterglow?

Response: experience (and it’s logical)

As Empereur Zorg pointed out, we have tested many 100 Hz screens (though they use interpolation).  Proper interpolation comes very close to a real 120 Hz.  Here is what we photographed with this function activated and then without:


And if we put the ''worst result'' images side by side and magnify:


The two afterglow images are twice as close to each other with 100 Hz.  Therefore, the size of the trail and blur behind objects in movement are mathematically divided in half.  We can then say that afterglow is reduced by half and this is what is confirmed by a simple visual test.  At 50 or 100 Hz on such a sequence, the gain is obvious with the naked eye!

You can convince yourself by looking at the above two images and purposely blurring the images with your eyes.  By stepping back, the much smaller size of images combined with the rather high speed at which they will move produces an image that is rather close to what will be actually seen on the screen.  You will notice that the 100 Hz blends into a single duck while with 50 Hz, the two images remain entirely separate.  And for this reason, we see more afterglow without the manufacturer even modifying the response time of its screen.

Either way, we will have to verify this with future 60 and 120 Hz monitors; however, it is unlikely the situation will be different.

Part 5:  3D movies and TV programs

3D will not only be found in video games.  The Japanese TV station NHK has been diligently working on the subject since last December and regularly offers such programs.  Moreover, it is this channel that enabled the company Orange to experiment with the retransmissionof the last French Open in 3D.  Orange has since announced the transmission of 3D soccer matches for 2010.

Before this and starting next year, Monster vs Aliens, Shrek 4 and How to Train your Dragon will be shot in 3D as well as other Disney-Pixar productions that will be released before 2012. James Cameron, Steven Spielberg and George Lucas also have projects of this type in the works. Jeffrey Katzenberg, the President of DreamWorks, hammers the point home in an interview accorded to Les Echos in which he says that all of this company’s productions will be shot in 3D in 2009.  Moreover, he adds that this isn’t an evolution but rather a revolution of the movie industry comparable to the arrival of color.

And for those that think such processes have existed for decades at Futuroscope or elsewhere, he says rather abruptly but succinctly: ''What I’m talking about is the next generation of images, way beyond what can be seen in the crude 3D movies in amusement parks.''

He also sees other interests: spectators will want to pay more for such movies and in addition,  they cannot be pirated.

Really? What about if monitors and TVs are 3D?

Part 6: Our fears

The principle of 3D seems rather simple: the 120 images per second are divided into 2 x 60 images, 60 for each eye.  If we close one eye, the other will see alternating colored/black/ colored/black images, etc.  Otherwise, the other eye should compensate for this and see black/colored/black/colored images at the same time in perfect alternation.  So is this done that easily without any problems? Of course, there is a risk of blinking combined with eye fatigue due to our brains having to reconstruct complete images into 3D from the two opposed signals.

We are anxiously waiting to test one of these monitors!