Head Mounted Display?


Klepto

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Hi all, with the imminent arrival of my Pandora (I love optimism) I'm looking into getting a head mounted display to use with it. This seems to be a bit of a niche area, with many of the best products being out of my price range. I thought I'd ask you guys for advice since there's a lot of gadget lovers here. My criteria are...
  • Reasonable price (no higher than 200 GBP)
  • Either non-occluded or monocular display
  • Resolution of at least 640x480, 800x480 would be ideal as that's what the Pandora screen is
  • Colour (16bpp would be enough)
  • Display quality good enough for extended reading of text
I've found a couple of products that seem to meet my needs but I know that display quality and extended use is often an issue. Does anyone here have personal experience of something that would fit the bill?

Thanks for your answers :)
 
I took a look at these a few months ago. I think the myvu with 640x480 is the best one around, looks decent and the resolution might be enough to use ssh on it. There are some european providers, but they're generally a bit more expensive and depending on your taste, less pretty. Although pretty is a strong word when it comes to video glasses, the only one that I thought 'pretty' was a sony prototype that looked like large sunglasses and were quite transparent, perfect for augmented reality. Too bad they're not coming out until 2010 or so.

I think I'll give the myvu a go once I get money, next spring maybe, I've got a bunch of other things I feel like spending on first though. Originally I though of getting a n95 and bt keyboard, but the pandora should do the trick as well.

Right I just reread your message, the price might be an issue as the myvu was something like 300€ in europe and quite a bit less if got from the us. There are cheaper one's but they've got inferior resolution, so I think you'll be looking at investing 300€ or so.

As for text, which was a priority for me too, I wrote to myvu and they said I should try the three week trial period they had, but I think that's a bit difficult with us being on the wrong continent and all. I didn't find any test reports on using video glasses like that, but if you're flush with cash then maybe you could do it :)
 
I've done a bit more digging. It seems that proper non-occluded stuff in my price range is gonna require a hw mod of some sort. I've built a fair few PCs and even soldered a bit but I wouldn't call myself a hardware guy so that's probably out. I'll have to make do without my Pandora when I'm walking about. It's a shame, augmented reality sounds like fun.

klikklak said:
I think the myvu with 640x480 is the best one around

I have their flash preview running as I type. It seems their biggest advantage is the large amount of peripheral vision they allow, most consumer grade HMDs concentrate on immersion. They are probably the least likley to cause fashion suicide, but I don't really care about that. The reviews seem good but nothing was mentioned about text readability, it was all about video and games.

Vuzix seems to be the other option, the AV920 is the same res and from the reviews I read it seems they have better optics. They do restrict peripheral vision a lot more but they have a forum and it seems they are happy to talk to customers and help with problems.

I found a few direct comparisons and both seem to do fairly well, perhaps with the Vizux coming out slightly ahead on picture quality. Even although they are very-occluded I'm leaning towards them for this reason. There are some posts on their forum about the screen being blurry at the edges, and a few that say this can be solved by moving them closer to your eyes. There are also posts confirming that you can use the VR920 (PC only, includes mic and head tracking) as a main monitor, I assume they use the same optics as the AV920 so that's reassuring.

klikklak said:
the only one that I thought 'pretty' was a sony prototype that looked like large sunglasses and were quite transparent, perfect for augmented reality. Too bad they're not coming out until 2010 or so.

That sounds good actually, I was more or less planning on upgrading them in 3 years or so once oled technology becomes more mature. I expect there will be much better HMDs on the market then, there are other people shooting for the same target as Sony.
 
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I think you're right about the vuzix, I'd forgotten those and didn't pay enough attention to them. They work with eyeglasses and have decent resolution. The thing with myvus is that they'd allow peripheral vision from above and below the glasses so it might be possible to use them while walking around. Say with some google maps mashup running. But the av920 looks like a better deal, the appearance is secondary like you said. Did you read the hmd thread on the general pandora forum? I just went through it twice while trying to catch up on my reading on pandora. The thing that got me was that fs stereoscopy seemed possible on _linux_, seriously, I thought that required special drivers and didn't have a standard. The av920's support that so thats a big plus for them.

Depending on my economic status, I think I will grab the av920's early next year.

Regarding oled: yeah, I'm a sucker for display tech and that's the main reason (and money and availability) why I've been looking at the wiz, but after using a nokia 770 I think I need a proper webpad/pandora. Can't wait for oled though.

HMD's bought now are very early adopter stuff and there's not that many applications for them I think, but it's interesting stuff. I think there's more location aware cell phone apps that'd be nice to have than proper free software apps, so maybe plugging hmd's to a n95 or something would make more sense. But the scene moves fast so at least web mashups should be usable fairly soon.
 
Nice thread! I was looking into HMDs a while ago and the vuzix AV920 felt like the best option for use with the pandora. So I'll be keeping my eyes peeled for these and probably save up some money ^^. Good to know that there is others who are interested in head mounted displays.
 
In reference to the lack of affordable non-occluded HMDs, it's not ideal but there is an obvious workaround using a webcam mounted on one of the legs of the display. A pen-type webcam that does 640x480 with a mic would be ideal, attached to one of the legs with Velcro strips or similar. It's not as good as non-occluded as long as your eyes are better than the webcam, but it does have the added advantage than you can make it IR. I've yet to find a suitable model that's on Ubuntu's list of supported webcams. You then (obviously) can display the forward view (or rear or wherever the cam points). EBay also sells small IR flashlights, so you could mount one on the other leg and have night vision as good as anything outside the military.

I was also thinking of using Velcro tape on top of the Pandora, and also on the back of a glove on my left hand to mount one of these as an input device. If there's something similar that does multi-touch it would be wonderful, but a simple mouse is easier to get working. Set up a highly customised interface with a virtual keyboard, put an overlay on the touchpad showing the virtual keyboard. It won't be ideal for text entry, but could serve as a pretty good input device. I'd expect to have to write some code for it, but I have already written a joystick event remapper in linux/gforth, I could modify it to make a scriptable mouse event remapper.

Add a battery powered USB hub of some sort, and perhaps GPS, head tracking, internet connectivity (if wifi won't do) and a chorded keyboard (I have an old USB gamepad to mod), mount it all in a shirt or jacket, and you can pretend to be a cyborg.:D

Perhaps I should change the topic title to 'Pandora as a wearable computer', or start a new thread. It looks like I can have a pretty impressive setup for under £600.

Edit: I guess it would be possible to mount another webcam and put them on the front of the HMD for stereoscopic bifocal vision, but that will be harder software wise.
 
Lol, what a wonderful thread! :)

Yeah, go ahead and change topic if you feel like it. HMD is a bit vague if we're going to be talking about full on cyborg sets. I actually didn't even dare to suggest mounting an webcam on the glasses, but like you said, it's an obvious solution. It's hardly ideal and I didn't even know about webcams that they come in pen size. The velcro touchpad looks neat, but I think it wouldn't be very comfortable if it's attached to a hand. Maybe hip mount would be better. On internettablettalk there was someone with a frogpad velcroed to his hip, so maybe that setup and put the touchpad above it? GPS is easy to get and an obvious thing to add, also 3g internet is something that I take for granted. Head tracking won't happen soon as it requires code, at least I'm not capable of coding that. And the av920 didn't have the hardware for head tracking.

The webcam attached to the glasses sounds like a huge kludge, maybe it would work better/be less heavy if the camera is in a front pocket of your jacket. That wouldn't be very stable though, it'd point where ever which would be disorienting. I think the glasses, 3g net, frogpad, touch pad are easy to get, but I have doubts about the webcam, that might not work all that well. It'd take a few moments to mount it all to a jacket, but once installed this setup might be surprisingly useful. What did they call fully enhanced people in snow crash? Bugs? Anyway, that time is coming soon :) (and about time, we've been living in the future for 8 years already :)
 
klikklak said:
It's hardly ideal and I didn't even know about webcams that they come in pen size.

If all else fails I can use a Lego brick webcam but there's other cams out there, this one looks nice and presumably I could swap the LEDs for IR ones. The problem is getting a cam in a nice form factor that works with linux.

klikklak said:
The Velcro touchpad looks neat, but I think it wouldn't be very comfortable if it's attached to a hand.

The idea is based on things like this, although one of the advantages of that particular pad is it can be stuck pretty much anywhere. I was thinking of putting it on top of the Pandora so I can have my hand in my pocket and still be able to use it by holding it on my hand and wrapping my fingers onto the touchpad. I'm not sure how practical that would be but I've seen handheld keyboards that seem to work in a similar way. It may also be better to put in on the underside of the wrist so you can hold some hardcopy in your hand as you type, but I guess you could just look at it, take a pic, and then use OCR on it :)

klikklak said:
Maybe hip mount would be better.

The advantage of that is that it leaves your other hand free, again that's really up to the user as long as there's some Velcro for the thing to stick to. I linked to the large version of the touchpad, there's a smaller one that may be more suitable for some places, but with an overlay and a virtual keyboard the larger one seems to make sense.

klikklak said:
Head tracking won't happen soon as it requires code, at least I'm not capable of coding that.

Hardware wise there's things like this, again drivers are the problem, but if I can get the raw numbers I can do the rest so it may be possible. The other thing needed for reliable head tracking is a compass, and while electronic compassess exist I haven't seen one with a USB interface. I'm not familiar with GPS, do they include a compass?

klikklak said:
The webcam attached to the glasses sounds like a huge kludge, maybe it would work better/be less heavy if the camera is in a front pocket of your jacket.

A tiny webcam shouldn't weigh much, but I accept that the weight of the headset is an issue. I believe the HMD comes with a strap that goes around the back of your head. It would be nice if there was a way to power the HMD from the USB hub, or at least move the battery elsewhere to reduce weight. Before I get one I'll probably post on the vuzix forums asking about things like that. Some kinda centralised power pack would be nice but probably not useful enough to justify the effort/expense.

klikklak said:
What did they call fully enhanced people in snow crash? Bugs?

I've not read that one, I read the first 3 of William Gibson's books, and some other sci-fi with similar ideas although I've not read a lot of what would be described cyberpunk. This looks an interesting read.

Another useful addition that hasn't been mentioned is a laser rangefinder, but again I've not seen one with a USB interface. Assuming all the features mentioned so far are possible it would allow you to take things to extremes if the software was written to do it. For example (using the rangefinder as a pointer) you could annotate the word with notes/file links in 3d, assuming the software was written to do it. It may also be possible to overlay the locations of wifi hotspots in the augmented world view assuming you gathered enough data to triangulate the position. I'm not planning on doing anything that ambitious but it doesn't seem impossible, and a lot of cool stuff should be within reach.
 
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Don't forget that you are only going to get S-Video interlaced at standard TV res, no point in asking for a high-res display when it will likely just go to waste.

Interesting concept though, I wonder what a BeagleBoard with native res would do to a VR920 over DVI, if it even accepts DVI/HDMI.

The BeagleBoard uses a seperate chip to encode the DVI over the outputs that drive the LCD in the Pandora, so the Pandora will not be able to output more than standard NTSC/PAL.

The BeagleBoard is a $150 OMAP dev board.
 
nubie said:
Don't forget that you are only going to get S-Video interlaced at standard TV res, no point in asking for a high-res display when it will likely just go to waste.
AFAIK that's still 625 lines, apparently the AV920 scales text down pretty well. I did think that perhaps I'd loose some picture sharpness using the TV signal though. I really wouldn't want to use 320x200.

nubie said:
Interesting concept though, I wonder what a BeagleBoard with native res would do to a VR920 over DVI, if it even accepts DVI/HDMI.
I didn't think of using the VR920 because of the input, but the head tracking would be nice, I know there's (incomplete?) code for a linux driver.

nubie said:
The BeagleBoard uses a seperate chip to encode the DVI over the outputs that drive the LCD in the Pandora, so the Pandora will not be able to output more than standard NTSC/PAL.

The BeagleBoard is a $150 OMAP dev board.
Does this mean that you can display one thing on the Pandora screen and another on the S-Video? I like the Pandora form factor, I'm not planning to use the HMD/touchpad exclusively. I'm aware of the Beagleboard but I don't think my hardware skills are up to that kind of hacking :)
 
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I just read a bit about the beagleboard. Buying that and a av920 with accessories (case, power, hub) would cost around 450€, with taxes around 600€. High, but doable. I think the main problem is that hmd's are designed for immersion and the see-through devices that are around cost a LOT. This might be too early for me to get involved in this as there's not very much code to use a setup like this with.

I read Kurzweil's book a half a year ago or so and it was quite good, it did get bogged down in various debates about the concept of AI a bit too much close to the end. One book that I think you should read is Accelerando by Charles Stross, especially the first chapters are about a guy with a wearable computer that functions as an 'meta-cortex'. Anyway, best of luck with the project, please post details about how it works when you get everything.

BTW, I don't think the beagleboard requires very much hardware know-how, it seems quite ready and just requires plugging various accessories to the ports that it provides.

EDIT: http://thefutureofthings.com/articles/54/L...yeglasses-.html the glasses by lumus seem very promising, in this 2007 interview they said they'd start shipping in 2008. Their webpage doesn't have a store yet, but surely they'll get it together in 2009?

EDIT: vuzix av920 from uk seem to be priced similarly to the pandora.
 
klikklak said:
I read Kurzweil's book a half a year ago or so and it was quite good, it did get bogged down in various debates about the concept of AI a bit too much close to the end. One book that I think you should read is Accelerando by Charles Stross, especially the first chapters are about a guy with a wearable computer that functions as an 'meta-cortex'.

Thanks for the pointers, I've heard of Charles Stross but not read any of his stuff. I'll keep an eye out for it but I don't have as much time as I'd like for reading these days, partly because I'm busy doing crazy stuff like this :)

Re Beagleboard: yes, it seems well within my hardware skills (which mostly involve plugging things together and switching them on). I'll stick with the Pandora as I have mine ordered, but at some point in the future I may get one for the DVI output. I've seen the Lumus page, it looks like just the thing, but as you point out it's not available yet. The Vuzix cost me 200 quid (excluding eye-shield), exactly the same as the Pandora.

My Vuzix arrived today, it's charging as I type this so I won't be posting full details for another 4 hours or so. I will however post some first impressions after unpacking the box...

Firstly I was out when it arrived, and it seems my neighbours must also have been out as I found it tucked behind my wheelie-bin. This has nothing to do with Vuzix of course, but I'm a bit disappointed with DHL. Upon opening the box I found everything in order and well packed with copious amounts of bubble-wrap. The package includes...
  • The HMD which is attached to the battery pack by a little over 1m of wire
  • A multilingual manual and a separate note explaining the adjustment of the nose bridge
  • A card giving details of their support line and telling me I get 10 minuets of free telephone support
  • 3 video cables (iPod, Nokia, RCA)
  • An optional tether strap that goes around the back of the head to keep the HMD in place
  • A couple of foam pads for the integral speakers
  • A couple of clips to help with running the cables about your person
  • A drawstring bag, presumably for keeping the HMD in although it won't offer any physical protection
I also paid extra for a USB charger (I needed one anyway) and the 'immersive eyeshield'. The charger looks to be cheap and nasty but it works well enough and comes with both 2 and 3 pin mains attachments. The eye-shield is more or less what I expected, it's made of soft rubber and seems fairly durable. I can't help feeling it's price (£15) is unjustified, ideally it should be included as part of the base package, but the HMD itself is priced reasonably so I don't feel cheated.

The battery pack is a lot smaller than I anticipated, around the size of your average mobile phone. It's also very light. I'd be happy to have a battery twice the size but apparently it lasts 4-5 hours which seems sufficient. The wire that connects it to the HMD comes out one end and on the other there are 3 sockets: AV in, micro USB (for charging) and a headphone jack in case you want to use your own headphones. The speakers that are integrated into the HMD are detachable which is nice, although I'll probably use them unless I encounter problems with comfort or sound quality.

The HMD itself is around the same size as I expected, although I thought it would be heavier. The build quality seems acceptable, around what you would expect from your average piece of consumer electronics. I had some problems with the nose bridge, it fell off when I was adjusting it, but it was easy enough to clip back into place. The nose bridge does seem a bit fiddly and is adjusted simply by bending the wire the pads are stuck to. I assume this arrangement was chosen because the HMD is designed to be used on top of glasses for those people who wear them, but as I don't I would have preferred a more rugged but less flexible design.

Upon putting them on there are a few things that immediately struck me regarding comfort and ergonomics. The legs don't have a curve at the end to hook around the back of the ears, I don't think this impacts their stability but it does feel kind of strange. Getting them on is a little uncomfortable for me, they feel like they are designed for someone with a smaller head, but once they are in place they are fine and I do have a particularly large head (that's me in my avatar). The speakers need bent into place but once this is done they also seem comfortable. Note that they are not in-ear buds, they are designed to sit outside the ears.

There's more peripheral vision than I expected, I'm wearing them as I type this and if I tilt my head up I can see under the HMD well enough. The exact alignment may change once I actually power them up and align the optics for best picture quality. The tether doesn't seem very secure, there are 2 rubber loops that slip over the legs, but there's nowhere for them to lock in to. The end of the legs are rubberised too, so friction seems enough to keep everything from falling apart but I won't be surprised if excessive head movement causes one side of the tether to fall off.

Even although I have yet to power them on I can just about see the screen area, I heard someone describe the picture size as 'an A4 sheet of paper held at arm's length' and that seems fairly accurate. It doesn't look quite as big as the 22" wide screen monitor on my desk, but it's close.

I'll know more later once I've switched them on, feel free to ask questions :)
 
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Well, I've switched them on now and so I can complete my review...

For testing I played Need For Speed: Carbon on Wii. It combines some moderately small text with high speed graphics so it seemed a good test. I have to say that on balance I'm very happy with the picture quality, the text was as clear as it is on my TV and there was no perceivable blurring towards the edges as some people have reported. There was some slight distortion of the picture shape, the edges were slightly concave, but it's not enough to be noticeable during use. There were no dead pixels.

The colours were not quite as vivid as I'm used to, but again it's not enough to make me feel disappointed, I was somewhat prepared for that from reading the Vuzix forums. Anyone who has played NFS: Carbon will know that it's hard to see where you are going at the best of times, and if the colour washout was in any way severe then it would have been a real issue, but it didn't impact on game play at all. I don't want to overstate this point, the colours were all there, just not quite as vibrantly as on my TV or monitor.

The on screen display is minimal but functional, there are options for: brightness/contrast, back-light intensity, and to select normal or one of the stereoscopic display modes. There's also an option to restore to factory defaults. I was very pleased to see that stereoscopic display can be selected manually as I'm not sure the Pandora will be able to encode the special s-video signals required to engage it automatically (it may be possible, I've not researched it yet).

My biggest worry was eye-strain and I'm pleased to report that my 20 minute session didn't cause any. I'll give it a longer test (a couple of hours) tomorrow but it really did feel like I was sitting 2 or 3 metres away from a fairly big TV. The fact that tilting my head cause the image to tilt was a little strange at first but it wasn't unpleasant and I soon got used to it.

I tried both with and without the eye-shield and didn't notice any difference in picture quality. Perhaps in bright daylight it may be an issue, but indoors I don't think it will be. The eye-shield is also not as effective at blocking ambient light as I'd hoped, I could see light at the nose and at the sides, but that may have been due to my big head or perhaps I just need to adjust it a little more. I certainly don't feel the eye-shield is a must-have item, and if you wear glasses then you won't use it, but it does provide a more immersive experience. I can see now why it is sold as an add-on.

The sound quality was fine, and surprisingly loud, I had to turn the volume down to around 15%. This may be partly because the speakers were too close to my ears, but I'd much rather have it too loud than too quiet. It was perhaps a little tinny, those who feel this is a major flaw can always detach the built in speakers and use their own headphones.

After I'd finished testing I gave my daughter a try. She needs glasses to see things more than a meter or so away clearly and while she was able to play a game of Guitar Hero 3 without them she did report it was a bit blurry. It worked better for her without the eye-shield and with her glasses but she had some trouble mounting the HMD on top of them. I think this could have been solved by adjusting the nose bridge, but it was already set up for me so we didn't attempt that.

I was under the impression that the AV920 had independent focus for each eye, but it seems not to have a focus adjustment of any kind. I think I was probably mistaken and it was an earlier model that had that feature. As it is I didn't feel the need for any kind of focus adjustment although it may have helped my daughter get a clearer picture without using her glasses.

On balance I'm very happy with my purchase, the picture is clearer than I'd dared hope and everything worked as it should out of the box. They also weigh less than I'd expected and allow some peripheral vision when not using the eye shield. There are a few minor niggles but nothing that makes me regret buying them. I was hoping to be able to leave the HMD around my neck when not in use, but the current tether makes that impossible. I may end up drilling a couple of holes in the legs to let me do this. The nose bridge is difficult to adjust, but it only needs set up once. The eye-shield isn't as immersive as I'd expected, but it's not really required anyway. I'd have been happy with a bigger, longer lasting battery, but 4-5 hours is reasonable.
 
I would really like to know how this works out with internet browsing. Can you try this for me? Is your wii connected to the internet and could you try browsing and reading a little bit? If the text is readable I would be very much intrigues to buy a vuzix hmd for my pandora.
 
xnopasaranx said:
I would really like to know how this works out with internet browsing. Can you try this for me? Is your wii connected to the internet and could you try browsing and reading a little bit? If the text is readable I would be very much intrigues to buy a vuzix hmd for my pandora.
My Wii isn't currently connected to the internet but I have an rj45 adaptor for it so it's just a case of running a cable across my living room. I'll give it a try soon, hopefully later today but I can't promise that. Some of the text in NFS: Carbon is quite small, probably smaller than in an 80x25 console, and it was all perfectly readable.

I played for a couple of hours today and still no eye-strain. I did get a bit disorientated when I first started but that soon passed, I think it was because I was driving a different car and spent more time travelling sideways. In situations like that my natural inclination is to turn my head towards the direction I am moving (as opposed to the direction I am pointing), but without head tracking that doesn't do anything. This won't be an issue for my wearable computer or general computer use but may be a problem in 3D games if you are particularly susceptible to motion sickness.

I made further adjustments to the speakers and while the sound quality is still a touch tinny it is very clear. The radio messages that I almost always miss when using my TV speakers were all much more understandable. This may just be because the lower range is missing but it was an unexpected benefit when playing that particular game.
 
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The upcoming Vuzix wrap 920AV (why they have 3 products with almost the same name seems like an odd marketing choice) with the see through lenses looks very interesting. We should hear the price soon and it may make for a perfect augmented reality set up with the optional clip-on USB cameras they mention that they are also planning. Also, the glasses don't look completely ridiculous.
 
@ Klepto
I love your signature: very funny when seeing that you're looking to spend £200 on a pair of video glasses!!
 
ttcircus said:
@ Klepto
I love your signature: very funny when seeing that you're looking to spend £200 on a pair of video glasses!!

Well spotted. I am a product of the times I live in, I have been infected by them. That doesn't mean I have to like it.
 
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