120 Hz and 3D-Glasses
Monitors capable of delivering a true 3D picture came out back in the last century along with shutter glasses that were connected to the graphics card and worked in pair with CRT monitors. But it looks like this technology is going to come to full bloom only in this year of 2010. Early models of shutter glasses disappeared along with CRT monitors because LCD monitors could not provide a refresh rate higher than 60-75 Hz. The alternative technologies have not taken off due to their complexity, quality issues, and protecting patents.
Last year I tested Nvidia’s GeForce 3D Vision glasses together with the first 120-gigahertz LCD monitor Samsung SyncMaster 2233RZ and predicted bright perspectives for that technology. It delivers high image quality in 2D and 3D modes. It works with rather simple-to-develop and manufacture monitors that are not protected with lots of patents and are not inferior to ordinary 2D monitors when you use them without the glasses. It is compatible with TV-sets and projectors. It connects to computers easily, not requiring a special interface from the graphics card. Critics would say that the glasses were expensive and the very idea of watching a TV-set in glasses was bad, but the recent Consumer Electronics Show has had the final say: very few of TV makers did not show new products with support for 3D stereo there and all of such products worked with active shutter glasses. Cable and on-air 3D broadcasting, video cameras for 3D shooting, a new version of Blu-ray with support for 3D, the refilming of old and the release of new movies in 3D: stereo imaging was the hot topic of CES’2010.
This is the near future, but what do we have today?
Today, we have two models of 120-gigahertz monitors that support stereo glasses: Samsung SyncMaster 2233RZ and ViewSonic VX2268wm (it sells as VX2265wm on the US market). Both have a diagonal of 22 inches and a native resolution of 1680x1050 pixels. You can complement them with the active shutter glasses GeForce 3D Vision that work with Nvidia’s cards only.
Two facts may be disturbing here: the native resolution and the brand of supported graphics cards. If you buy an expensive monitor today, you want a Full-HD resolution of 1920x1080 pixels. And AMD has left Nvidia behind on the graphics card market by releasing the Radeon HD 58xx series and it is yet unclear when Nvidia is going to catch up with its opponent.
Fortunately, both problems are going to be solved soon. Acer is expected to market its 23.6-inch 120-Hz monitor with a resolution of 1920x1080 pixels in February or March. ASUS and ViewSonic plan to introduce such products, too, and other makers will follow the suit soon. There are already at least two makers of LCD panels for such monitors: CMO and LG.
It’s somewhat more difficult with AMD/ATI. The company had been expected to showcase the playback of stereo Blu-ray movies on its graphics card at CES and to enable the stereo mode in its Catalyst 10.1 driver, but neither happened. AMD is planning to release stereo glasses compatible with its graphics cards not sooner than the second half of 2010. But if they do enable stereo mode in their drivers, third-party glasses may come out even sooner than AMD’s own ones.
Most importantly, purchasing a 3D monitor makes sense even if you don’t plan to buy stereo glasses or if you have an AMD graphics card. Why? First, a monitor is usually expected to serve for 3 to 5 years and stereo glasses will have become a standard device, compatible with all graphics card brands, by that time. And second, 3D monitors are superior to their “flat” counterparts in response time even without any glasses.
The fact is stereo glasses impose strict requirements on the real (not only on the specified) response time of a monitor. The monitor must be able to refresh the picture during the period when the glasses are opaque, which lasts for a few milliseconds. If this requirement is not met, there will be various unpleasant visual artifacts in 3D mode, making the monitor unsuitable for showing stereo video content.
Thus, although stereo monitors do not hold the world record in terms of response time (the 2233RZ is as fast as 3 milliseconds while a lot of ordinary monitors have a response time of 2 milliseconds), they prove to be among the fastest available models if you set their refresh rate at 120 Hz. They combine this high speed with a very low level of RTC-related artifacts. So, if you are into games and want your monitor to be as fast as possible, you have no other choice but consider the 3D Vision compatible models. You can have one with a resolution of 1680x1050 today or wait a little for the 1920x1080 model to come out this spring. You can buy the glasses later on and I guarantee you won’t be disappointed (if you don’t believe me, just watch James Cameron’s Avatar in a 3D cinema).
What about the competing technologies if any? To cut it short, their fate is sad. There are no real opponents to the active shutter glasses today. The whole story goes like this. There are two alternative technologies with cheap passive glasses: interlaced polarization (Zalman’s Trimon) and polarization plane adjustment (the iZ3D). The former technology lowers the monitor’s resolution by half in 3D mode (thus, a matrix with a native resolution of 2160x1920 would be required to show Full-HD video) and has very narrow viewing angles. The latter technology is too expensive as it implies the use of two LCD matrixes in one monitor and still suffers from a persisting problem of the image tripling due to insufficient separation of the right and left frames. Monitors with these technologies are manufactured by two companies only (Zalman and iZ3D, respectively), and there are no such TV-sets at all.
You may also come across the idea of stereo imaging without any glasses. I must assure you that this idea won’t go beyond specialized journals and exhibitions in the next decade. The problem is in the very basics of the formation of a stereo image: each eye has to be shown an individual picture. There is only one way to separate the two images in the glasses-free concept – the spatial one. The left and right eyes are looking at the screen at slightly different angles. Thus, there must be a filter on the surface of the matrix with micro lenses or small slits made in such a way that the user saw different pixels at different angles of view.
The fatal problem with this technology is that a man’s eyes are only some 65 millimeters apart. Thus, if you move your head a few centimeters rightward while watching video, your left eye will get to the position where the right eye has been and will see the picture meant for the right eye. The right eye, in its turn, will either see the image for the left eye (the stereo video will be kind of upside down then) or just a jumble of frames in which the left frame will merge into the right one depending on what part of the screen you are looking at. Thus, auto-stereoscopic monitors (those that do not require any glasses) have a few strictly defined points from which a normal 3D picture can be seen. But the main problem is that as soon as your eyes are deflected from those points, you lose the sense of space and your eyes and brain begin to receive a mix of right and left frames, which will make your head ache very soon. This technology is okay for exhibitions and other public entertainment where visitors come up for a couple of minutes to move their heads around searching for a pretty image and can just turn away if they don’t like what they see. But it is no good for normal home use.
Summary: monitors with support for stereoscopic glasses are interesting not only for their ability to work with such glasses (even though this application is quite exciting in itself) but also as monitors for devoted gamers as they boast a very high response time with a minimum of visual artifacts. Just don’t forget to set the refresh rate at 120 Hz in your graphics card driver!