Olympus Eye-Trek FMD-700
This was my very first HMD, purchased in back in 2000. They are the top of the line of the Olympus range and are still among the most advanced video glasses I have ever seen. They accept PAL and NTSC video signals (both composite and s-video) as well as VGA input from a computer. The lenses are very high quality, providing a clear sharp picture with no distortions across the entire display. The set-up menu provides extensive picture controls for brightness, contrast, tint etc, and even remembers separate settings for PAL, NTSC and VGA. Sadly there is no 3D capability, and the resolution is low by modern standards, because in every other respect, this is the best HMD I have ever used.
The specs list a resolution of 180,000 pixels, but they use fancy signal processing to emulate a display of 720,000 (basically they soften the image digitally). The display is very good for video sources, but no as good for reading text on the computer. I am very sorry Olympus abandoned this range of displays; had they carried on developing them, I'm sure they would have Full HD 3D models on the market by now.
Olympus Eye-Trek FMD 250W
The 250W is actually a step down from the 700 model above, but it had the advantage of a native widescreen display. As far as I know, this was the only 16:9 HMD on the market for many years, and the screen is very impressive, despite the low resolution (240,000 pixels). It accepts composite and s-video, but PAL only, although there was also a separate NTSC version available. As with the other Eye-Trek models, the optics are first-class, and the image was very sharp. Unfortunately this also means the low resolution is unmistakable - it had a distinct "screen door" look to it.
All versions of the Eye-Trek do have the same weakness, unfortunately: the earpieces are flimsy and have a tendency to break. You have to be careful, because replacements are impossible to find...
Rimax Virtual Vision 4.0XL
The Rimax has a 640x480 display, so is higher than any of the Olympus models (which were out of production by then) but in every other respect it's a pretty poor product. Compared to the Eye-Treks, the field of view is very small (25 degrees) and the colour contrast is awful; it's almost impossible to adjust the image to a satisfactory level. It accepts composite PAL and NTSC, but no 3D. I don't think the company exists any more (and if they do, shame on them).
Vuzix AV920
I'm sure Vuzix needs no introduction
![Wink ;)](./images/smilies/icon_e_wink.gif)
When I bought these I opted for the AV (video) model instead of the VR (computer) model because I wanted them primarily for use with DVDs. I could never get them to sit comfortably, and I had a very hard time finding the "sweet spot" where both displays were properly centred over my eyes. A few years after their release, Vuzix issued a firmware upgrade adding side-by-side 3D, which made them much more useful to me.
Generic Chinese HMD
These are actually better than I thought they would be - although my expectations were low, so that isn't saying much. The image is surprisingly superior to the Vuzix AV920, although it is nowehere near as good as the Wrap 920 or the Zeiss Cinemizer (I think I go through HMDs the way most people go through headphones). The can display field-sequential 3D, but the lenses are very poor (the edges of the picture are very fuzzy) and - ridiculously - you can only operate them using a remote. Who came up with that one?
The Headplay
When I first saw the specs for these I thought they were sure to be the ultimate HMD. High resolution! Good connectivity! 3D compatible! Focus and IPD adjustment! How could these possibly go wrong?
In practice I find the Headplay absolutely maddening. On the one hand, the display is wonderful. The colours are deep and rich, the FOV is immersive and it can connect to virtually anything. Unfortunately - for me - it's all downhill from there. I have never been able to get that ridiculous golfing hat to sit properly on my head; it never seems to want to stay in the right position. Also my unit doesn't do well with AV signals - composite or S-video. The picture has distortions, as if there is interference from something, and it has a hard time moving from PAL to NTSC. The 3D, of course, is no longer compatible with anything, and because the unit uses a single display for both eyes, I find there is noticeable ghosting (which is really unnecessary in a head-mounted display).
I really want to like these more than I do, but there are too many negatives for me, sadly.
The Vuzix Wrap and the Cinemizer
Quite a lot has been written about these already, and they are very similar products in many ways. They both have the same resolution and field of view, and they both display side-by-side 3D.
The major advantage of the Vuzix is the optional VGA connector. The Cinemizer is composite video only, but the colour contrast is actually better; you can make out a bit more detail in the image, even though the resolution is the same. Having said that, Vuzix has the better brightness and contrast options with their onscreen menu. Cinemizer simply has three pre-set brightness levels, with no other adjustment possible. In 3D mode, Cinemizer also cannot swap over the left and right images; if you have an image formatted for cross-viewing, you're out of luck. Without a computer connection, though, the issue doesn't come up very often.
Cinemizer has a built in battery, and can be recharged through a USB port - much more convenient than having to constantly swap out the AA batteries in the Vuzix power pack. Also Cinemizer gives you a headphone socket if you want to use your own headphones. On balance I find myself using the Vuzix more often, but they are both good products. If the Cinemizer had a VGA connector it would be a much harder choice. Now if only they could produce a Cinemizer with an HD display, OLED screen and HDMI connection - then you would really have something!
Sorry for such a lengthy post, but I've been meaning to sort out my previous HMDs in my own head for some time. The prospect of receiving the Wrap 1200 in a few days (
![Very Happy :D](./images/smilies/icon_e_biggrin.gif)