VFX-1 Headgear vs I-Glasses

Among the many peripherals you can add to your personal computer are the unusual and rather expensive devices called Virtual Reality headsets. With a growing number of games supporting these new add-ons, users will experience what some already described as the ultimate experience in gaming.

However, as four different manufacturers are already present on the market with their respective products, you may have a hard time choosing the right headset. This motivated us to write a comparaison between the two more popular headsets available right now: the VFX-1 Headgear from Forte Technologies and the I-Glasses from Virtual IO.

We will explore several aspects such as image and acoustic quality, connections, games, ergonomy and the VR experience itself.

Cables and cards

If you thought you had too many cables around your PC, wait until you connect a VR headset. Both come with several cables that will plug into various interfaces. The VFX-1 uses a 16-bit card called VIP (VFX-1 Interface Protocol) that you will have to install into the PC through a 16-bit ISA slot. A first connection starts from the VIP card to the VESA connector of your video graphic card. It is therefore important to find out if your video graphic card is VESA compliant. A list of known incompatible graphic cards is available directly from Forte Technologies at their technical support department. A quick way to find out if you can install a VFX-1 into your machine is too look for the presence of a feature connector on your VGA card. If you don't have one, forget the VFX-1 or buy a card that features this connector. Keep in mind however that it is not because you have such a connector on your VGA card that the headset will work correctly. Some cards have a non-standard feature connector that may or not work with the VFX-1, so contact Forte Technologies before giving out the money for the headset.

After you have checked that your card works with the VFX-1, you must choose an address for the card. The default address (260h) will work in most cases, but if you happen to own a device that uses the same address, don't worry because you will be given three other possibilities (280h, 2A0h and 2C0h) through jumpers on the card.

The last series of operation is the connection between the headset and the PC which is done by an eight feet long (2.43m) 26-pin D-connector. This cable contains video, audio and head tracking signals. For the audio part, the headset comes with two mini-phono cables that link the VIP card to your sound card. The first one is for the audio from your sound card and the other is for the built-in microphone of the headset that allows player-to-player communications during games that support this feature.

Finally, the Cyberpuck is a kind of virtual joystick that plugs into either the VIP card or the headset through an ACCESS.bus cable. The ACCESS.bus PC Connectivity Standard allows you to connect up to 125 peripherals to a single host. The advantage of this technology is that you can keep your mouse and your joystick connected while using the VFX-1, which is not always possible with the other VR headsets.

The I-Glasses from Virtual IO come in two models: the video and the PC versions. An upgrade for the video version allows use of the headset with a PC to add head-tracking possibilities. The I-Glasses need an interface to work with the PC because they only accept a NTSC signal for the video. This means that the VGA output from the video card must be converted into the adequate NTSC signal and this is what the PC interface does. This black box has two VGA connections: one for your monitor and the other for the VGA card which you will connect to your PC through a 15-pin video cable. The head-tracking cable is a 9-pin serial cable going from one of your serial ports to the head tracker connection on the PC interface. Using serial ports for head-tracking was not the best idea as most users have their mouse connected to the first port and the second usually dedicated to the modem. One other connection links your sounds card to the interface. Like the VFX-1, a mini-plug cable is used to make the connection. An additional audio connector located on the interface allows you to use speakers at the same time. Finally, as the signal conversion requires some energy, you will have to connect the PC interface to a 9 volt power supply if you want to use the I-Glasses.

Image and sound

What is probably the most important in Virtual Reality is what you see on the screens placed in front of your eyes. There is no way you can feel immersed in a virtual world if what you see is a rough 3D view. With today's standards, the game must use textured-graphics that look realistic and preferably have SVGA possibilities which of course implies you can display SVGA graphics. This last point is where the VR headsets fail. With about 180,000 pixels for left and right screens, the resolution is not high enough to display the original image with clarity. The best example of this is the standard DOS text screen with 25 lines and 80 columns. While it is possible with fine tuning to read such a screen with the VFX-1, it is absolutely impossible to read anything with the I-Glasses. But then of course, you don't buy a VR headset to do your word processing!

The VFX-1 has a maximum resolution of 640 by 480 with 256 colors while the I-Glasses only have 16 colors at the same resolution. Besides the MCGA standard (320 by 200 in 256 colors) that both can display, the VFX-1 is also capable of 320 by 400 images in 256 colors. Such resolutions can be found for example in Flight Unlimited by Looking Glass Technologies and Ravenloft by S.S.I.

The 0.7" (1.78 cm) color liquid screens used in the two headsets have a similar amount of pixels: 181,470 for the VFX-1 (789x230) and 180,000 for the I-Glasses. With games using normal 320 by 200 resolution, both headsets will give you entire satisfaction regarding image quality. However, unlike standard monitors, there are no controls to adjust brightness or contrast.

One of the biggest differences between the two headsets is the focus control. The VFX-1 has two controls to adjust your vision: the IPD (Inter-Pupillary Distance) and the focus. The IPD control will let you move the two eyepieces so that each eye is aligned with one screen. For the focus, turn the optics clockwise or counterclockwise to obtain the best image. Compared to the I-Glasses that don't require any adjustments, the VFX-1 surely lacks ease of use. The I-Glasses also allow anyone wearing glasses to use the headset without adjustements because the distance between the optics and your eyes is larger than with the VFX-1.

The headphones for both headsets, although very different, provide users with an excellent sound. The VFX-1 uses two AKG high fidelity stereo headphones that completely cover your ears and hence, isolate you from the sounds surrounding you. Although the headphones of the I-Glasses do not cover your ears like the VFX-1, their position is adjustable. There is also a volume control button to set the sound to a comfortable level on the I-Glasses.

Ergonomy

If you compare the two headsets, the first thing you will notice is the size difference. At first glance, the VFX-1 looks like a helmet that litterally covers your head. This design has the immediate advantage to immerse you into the virtual reality as you can't see the external world at all. With the I-Glasses, you won't have the same immersion because even with them on your head, you still see a part of the real world when you look down. The other difference is the weight. Even if the weight of the VFX-1 is evenly distributed over the head, in contrast of some other headsets, its weight of 2.5 lbs (1.1 kg) is three times larger than I-Glasses's weight with 12.5 oz (0.37 kg). We tried several games with both headsets, and found that playing 30 minutes with the VFX-1 was a maximum while one hour and even more was no problem with the I-Glasses. You will, however, have a red mark on your forehead after using them that is caused by the foam forehead pad.

To return to reality while keeping the headset on, the two headsets do this in different ways. The Smart Visor when flipped up on the VFX-1 allows you to continue working on your PC. If you want to go back to the game, just pull it down to immerse yourself into the virtual reality. The I-Glasses have a Clip-on visor that can be detached from the headset. You will still have the two screens in front of you, but you will see the surrounding world through them in the background.

Virtual Reality Experience

As mentioned above, the VFX-1 is the best headset available when it comes to immersion, but Virtual Reality is not only limited by this aspect. The degrees of freedom have an important role to play as they will limit your movements in the virtual world. The three degrees of motion are pitch, roll and yaw. Pitch is when you move your head up and down exactly as when you say "yes" with your head. When you tilt your head from right to left or the oppsite, you are doing a Roll movement. A Yaw motion is when you turn your head from right to left for example. Not all VR headsets have the same specifications regarding these motions except for the Yaw which has a value of 360 degrees. For the other movements, check out our comparaison chart below.

The apparent size of the image you will watch with the headset is also of importance. If what you see is too small, you won't feel immersed at all and it will as if you were watching a monitor from the other side of the room. The Field of View (FOV) influences this parameter and the greater it is the bigger the screen will appear. With a FOV of 45 degrees, the VFX-1 is like watching a 120" (3.04m) screen at a distance of 11 feet (3.35m). The I-Glasses have lower values with a FOV of 30 degrees which represents a 80" (2.03m) screen viewed at the same distance.

Games

Most of the games were not designed with VR support in mind, but the few that are belong to specific categories. The first category contains 3D first-perspective games such as Heretic, Descent and Dark Forces. You will be able to use the head-tracking possibilities that will allow you, for example, to turn your head to the left while moving in another direction. If the game features a 3D stereoscopic mode, you will see the game in 3D like Descent and System Shock. The second category includes the flight simulators with titles such as Flight Unlimited, TFX 2000 and Inferno.

There are of course other games you can play with, but you will find limitations for the different motions. Some games will only feature yaw motion while others will support pitch and yaw. Overall, about 20 games fully support the three degrees of freedom offered by the VR headsets. It is not much, but considering the headsets were released in 1995, we can expect a growing number of games to be released in 96 and the future. After all, according E. Ted Prince, President of Perth Ventures, the VR market will become a $6 billion industry by 1999 with $1.6 billion for the VR peripherals.

Key features

Until now, we have compared several aspects that all VR headsets offer (screens, connections, sound, head-tracking, etc...). It is now the time to talk about the unique features that each headset offers.

The Cyberpuck, as mentionned in the first paragraph, is a two axis joystick for the VFX-1 that replaces the use of the mouse and traditional joystick. I found it to be really efficient in most of the games I tested out, especially with Dark Forces and Mech Warrior II. Of course, if you prefer to continue with the mouse or a joystick, you can always turn off the cyberpuck.

The I-Glasses have an advantage over the VFX-1 that they accept any NTSC signal which means you can connect them to a VCR, a console and a TV. However, don't expect to use head-tracking features with them, that won't work!

The two headsets come with a bonus CD-ROM. The CD from Forte Technologies features shareware versions of Heretic, Zephyr, Darker, Quarantine, Descent and Magic Carpet. The one from Virtual IO has Heretic and Descent shareware versions with drivers for Dark Forces and Magic Carpet plus the game Ascent. Both CD's also contain various demos to show the 3D possibilities. In the I-Glasses package, you will also find a video tape that explains how to use and connect the headset. In chapter 5 of the video illustration, a short 3D movie will be presented and I guarantee you will be surprised by the amazing effect of stereoscopic images.

Conclusion:

For myself, there is no doubt that the VFX-1 has superior performances over its competitors. The immersion feeling is absolute and really provides you with an intense experience. Try out MechWarrior II with the VFX-1 to see what I mean!

On the other side, the I-Glasses with their greater connection possibilities offer a more polyvalent product with which you can play consoles, and watch movies. It is not called the Personal Display System for nothing!

In other words, if you want Virtual Reality exclusively, don't hesitate and choose the VFX-1, but if instead you are looking for a product you can use on your PC for VR games and also with a console or a TV, then the I-Glasses would be the best choice.

Comparaison chart

Features	VFX-1 Headgear	I-Glasses
Resolution	181,000	180,000
Color Display	Dual 0.7" active-matrix LCDs	Dual 0.7" active-matrix LCDs
Apparent Size	120" screen at 11 feet	80" screen at 11 feet
Field of View	45 degrees Horizontal 35 degrees Vertical	30 degrees Horizontal 22 degrees Vertical
Pitch, Roll	70 degrees	60 degrees
Yaw	0-360 degrees	0-360 degrees
Immersive	Yes	No
Video Signal Input	Direct RGB-RGB	NTSC conversion
3D decoding	Frame sequential	Field sequential
Tracker location	Centered on crown of head	Back of head
IPD adjustment	Yes	No
Microphone	Yes	No
Immersive headphones	Yes	No
Adjustable headphones	No	Yes
Volume control	No	Yes
Can wear eyeglasses	Yes, but uncomfortable	Yes
Compatibility	PC only	PC, Mac, Sega, Nintendo, Jaguar, 3DO, Sony PSX, VCR, TV.
Weight	2.5 lbs	12.5 oz
Interface	Access.bus ISA card	PC Interface through RS-232 serial port
Peripherals	Cyberpuck and others to come	None
Needs power supply	No	Yes, included
Warranty	One year	90 days
Retail price	$995	$599 for the video version $799 with PC upgrade