Epson Moverio BT-100

In the ancient days of the early 2010's I wrote a review on the Epson Moverio BT-100.

April 6, 2012

I've had these for a few days now. Here are my initial impressions.

This is an interesting toy. There are two components to it: the glasses, and the Android box the glasses plug in to. First I'll focus on the Android box. Since there is no touch screen there is a touchpad on the device. This touchpad is not very intuitive. It took me far longer than it should have to figure out how to do "swipe" gestures (like unlocking the screen). The problem was I kept trying to do a more click and drag gesture like on a laptop, which is, as it turns out, quite different. So on a laptop when not using a physical button you might "double tap" the touchpad to get a click registered, then drag your finger. This touchpad works pretty much just like a touch screen: tap and hold, then drag your finger. Which makes sense I suppose since this is an Android device, it just felt rather unnatural on a touchpad initially.

This is more of an Android issue, but it can be difficult to determine where the mouse cursor is. Typically on devices with touchpads (laptops and such) the cursor is always on the screen. Here the cursor is only on the screen when you are touching the touchpad. This is probably so that apps don't have to implement one interface for touchscreens and one for mice, but it can be a bit jarring from a user perspective. It's also extremely difficult to type with the onscreen keyboard (I'm having to use the predictive text quite a bit).

This device runs Android 2.2 (froyo) which is a bit annoying from both a user (apps missing in app store) and a developer (Froyo NIO bug frustrated me) perspective.

One of the key things this thing is advertised to be for is to watch movies (though I did not buy it primarily for that). First video format support is severely lacking. I had to install another app to watch the videos I have. Netflix is available and works fine, pretty much. The second problem with watching any video is there is some sort of latency issue between video and audio (a noticeable 2 second or so audio delay).

For developers, apparently you have to submit a request on Epson's website to get the drivers (plugging it into either a Windows or Linux box it only comes up as a USB Mass Storage device and it does not show up in ADB). I did that but got tired of waiting for a response, so I ended up rooting mine and activating adb network access so I could upload and debug my app over WiFi. This works pretty well, but I don't like having to root something if I don't have to. Also since I was in no mood to type the adb commands in a terminal on the device I ended up side-loading DroidSSHd. This was all fairly easy, and the main benefit is not having to be tethered to a computer to deploy code and debug it.

Now to the second part, the glasses themselves. So there are other glasses out there (Sony HMZ-T1, Vuzix, etc.) but I've only had a brief experience with the Sony HMZ-T1 and not really enough to make a complete comparison. However the most obvious different between the two is the Moverio is transparent and HMZ-T1 is not. The HMZ-T1 is probably better suited for watching video due to it's higher resolution, better contrast, and OLED display though you'll have to plug it into another device to drive it since I think it's just a monitor. On the Moverio side since it is transparent you can see around you if you remove the dark plastic piece on the front, potentially allowing for some interesting AR applications and allowing you to interact with your environment without taking the glasses of (not that I recommend wearing them with other people around, you'd look ridiculous!)

Both support 3D, however the Moverio loses half of its horizontal resolution in 3D mode since it stretches the screen across both glasses. This is probably a problem limited to the Android portion of the device and I would imagine if Epson releases any adapters to plug the glasses into other devices they won't necessarily share this same limitation (BIG POINT here: you can't plug anything into these glasses other than the included Android box. That means no computers, game consoles, smartphones, etc.) That said, I wouldn't recommend buying a Moverio on the hope that Epson releases adapters for it.

For the purpose of AR apps it is best if black portions of the screen are as transparent as possible (so you can see the world behind it. If you take off the dark plastic piece on the front of the glasses, black areas are fairly transparent. But like any projector I've ever used, black is really a dark gray on this thing (better if you decrease the brightness). So, it's not ideal... but not too bad either. We may have to wait until good transparent OLED glasses come out for that kind of experience.

The screen is advertised as an 80 inch screen some distance away. If you've never used video goggles before I'll just say that is pretty accurate. However here is an easy way to get an idea of how large the virtual screen is if you don't have an 80" tv handy: take your cell phone, play some video on it, and put it about 10 inches in front of your face. That's what it feels like. It's not too bad when watching video (though the less than 720p resolution is unfortunate) but it is really damaging for AR and VR apps. Take your phone and turn on the camera keeping it about 10 inches from your face. That little window is all you have into the virtual worlds you may be considering creating.

Finally, comfort. In my humble opinion there is none. My nose and ears are uncomfortable wearing this.

Now with all that said, I still am glad I bought this product. Why? I've always wanted to try my hand at an augmented reality project requiring more immersion than just pointing a phone. Technically this device makes it relatively easy to experiment. It's wireless (just a cord going from the glasses to the Android box, but the Android box has WiFi and a rechargeable battery so you can walk around with it untethered), it supports stereoscopic 3d, and it's programmable using the widely available Android SDK. There are significant issues and personally it feels like a beta product intended for developers, tinkerers, and scientists.

Ultimately this is an expensive product for what it delivers now. If all you want to do is watch movies and play games, get a tablet for half the price.

A couple suggestions to Epson and anyone else making something like this: add a gyroscope to the glasses, increase the field of view (in AR apps we don't need to see the borders of the image), make an API to switch into 3d mode in software (and please don't cut down the horizontal resolution just because it's difficult to change the resolution of Android while it is running, just double the horizontal resolution all the time and draw the screen twice in software), fix the audio latency, make it a little more comfortable and look less like some bad 80's scifi movie, and make the keyboard navigable with the directional pad. I feel many of the faults are in the software side so, Epson, hire a few good Android developers and Linux kernel hackers!