Introduction

I would like to thank Zalman for supplying the review sample.

We get to take a look at the Zalman ZM-M215W 3D Monitor today. With the third dimension picking up speed in the movie theaters, for games and Blu-Rays, it is obvious that we will see actual 3D monitors on the market nowadays. Zalman showed off the technology quite some time ago - well before such a feature really caught on, but now that it has they are releasing updated models of their LCDs. The new line-up is available in 21.5" and 24". Both of them are 16:9 so that you should not have any black bars when watching modern clips in 3D.

Specifications:

Different Approaches To 3D

While there are active and passive 3D methods, most offerings available today use passive methods to achieve depth of field. There are two main approaches: Colored Glasses and Polarized Glasses. The one active method being used today is NVIDIA's 3D Vision, employing active shutter glasses.

Colored Glasses

Image courtesy of HowStuffWorks

There are various ways to achieve the illusion of 3D. One of the simplest and most well known approaches are color filters for each eye. The human viewing apparatus is sensitive to the three base colors: red, green and blue. Having glasses with a red and cyan filter, any images which employs this technique can be viewed in 3D. Such images are simply created by placing that same image on top in red and blue over the originaly, but slightly dislocated to achieve a depth of field effect. Such colored glasses are a passive viewing method, as they do not have a power source and the 3D effect stems from the display, not the glasses.

Polarized Glasses

Image courtesy of HowStuffWorks

Another passive approach is with the help of polarized glasses. There are two main methods of polarization: linear and circular. The approach is similar to that of the colored glasses, but instead of color filters, this system employs polarization filters. The filters for each eye only allows the properly polarized images to be seen by that eye, cancelling out the other image. By doing so the 3D effect is attained. The upside of linear polarization is the fact that more than one person can watch the screen at the same time, while the downside being the inability for the person to move or tilt their head, as this will cause one layer of the 3D image to bleed into the other. This effect is not present with circular polarization. Zalman uses circular polarization for their 3D monitors. This system is similar to the Real 3D used in modern 3D theaters.

Shutter Glasses

Shutter glasses do not have the limitations of polarized glasses, as there is no limitation in viewing angle and a great number of people can watch at the same time. Achieving the desired effect requires a 120 Hz display or projector, as the shutter glasses alternate between two images - one for each eye, creating a 3D effect. That cuts the actual frequency at which each eye receives an image down to 60 Hz. Anything below that will result in noticable flicker in the viewer's eyes. NVIDIA is using such technology and is pushing monitor, DLP and HDTV manufacturers to offer displays which can output 120 Hz.

Other Methods

There are a few other methods out there, some of which do not require you to wear any glasses, but none of them are ready for prime time and do not tend to offer the depth of field we have seen in movies like Avatar. Nonetheless, 3D is the way of the future, with movie theaters seeing additional revenue when a movie offers such an extra and Blu-ray now offering 3D right at home - further differentiating itself from the DVD standard and thus pushing more people to switch. The methods employed today are by no means the end of the line. Actually, this is the very beginning and I am sure there will be vast improvements in the future.