Hello Okta,

i din't use exactly the lenses from the video. I read the leep-optics patent and the author stated, that with a lens-system with more focal length (about 100mm) and a 7" screen would be a better choice.
( http://www.freepatentsonline.com/4406532.pdf )

So i ordered
2 x 75mm diameter, 100mm focal length
2 x 50mm diameter, 125mm focal length.

from http://www.lupenshop.de/content/lupensh ... talog/1534
( i know its a german site, but no prob for me as i live there ).

It is sort of working, but...

1. only the center is in focus.
2. i can't get the immersion, im looking for (only about 45°, a lot better then ordinary video-eyewear, but still not enough)
3. the colors and the geometry is distorted of course. (geometry can be corrected, but colors...)
4. the screen size seams to be limited to 3" - 4". ( i loved your idea with the 7" screens )
(I have 4 front-mirrors too but didnt try yet. )

Tried to look at a stereoscopic image, but as i sayed, only the center is in focus. The image is very blurry at the sides. That stresses my eyes very much.
Can't look for long time this way

Maybe i need to test a huge lens, that ist aspherical, aplanar and achromatic, but they are rare and VERY expensive.

Good idea to use a doorspy lens. Is it of good quality?
Would like to test something like this, but its too expensive just for testing:
http://www.amazon.com/dp/B002ULH56O

So not realy a progress, sorry.

And the limited space for a huge dome or curved screen is my problem too

Greetings

Hows the hmd doing? Any problems? Working good?

This display might have some impact on the HMD world. It is Hitachi's 6.6-inch display 1600 x 1200 pixels on a transmissive IPS panel. Here is a direct link to the article;

http://www.engadget.com/2010/10/06/hita ... d-to-tabl/

Joe Dunfee

Yes, I saw that too! It is very interesting, but I am sure it will be a while till it hits the market. And it is unlikely at best that a standard video input board will be made for it, that only happens in cases of high demand.

Still positive, though!

I think the best way to create an HMD would be to use a pico projector that has no lens such as the microvision showwx, pico projectors that have no lens are always in focus. Which is something that is very important for an HMD. Why not build an HMD first using 1 pico projector and if it works then use 2 for a passive 3d setup. There must be other pico projectors out there that are 640x480 or 800x600 with no lens that are affordable. The good thing about the showwx is that the projector is mint sized, so you could take it apart and remove the case and get to the mint size projector and hook it up to your own battery source, this way you could further bring down the size of it so you can fit it snug into a kind of helmet display. I think the best setup would be 2 of these pico projectors beaming to curved screens and a fresnel lens and circular polarized glasses. 6 dof tracker and microphone. This would be awesome, I am sure the parts could be found for a good affordable price.

The other idea is that, archos has come up with some portable media players under $100 with some thin and good size screens. very light as well.

When I click that link all I get is a bunch of symbols that I cannot read, what is this link all about?

EDIT: I have found out what this is now, thanks for posting. Looks very interesting but probably won't be in a HMD for a while now at least a consumer HMD as the article I read said it will be on broadcasting equipment first.

Anyone thought of taking a HMD like the avr920 and then removing the optics on putting in the leap on the cheap optics that offer near to 90 degrees field of view?

Still you need displays of proper dimensions and I think those are too small for the leap on the cheap optics.

Sorry if thoughts from an inexperienced person interrupts the dialog here, so feel free to ignore me.

I have continued to study your equipment, and the various idea that have been promoted on this board. I am trying to understand all the challenges with these designs and how to obtain a wide field of vision. In the past, I had tried to lay out a mirror arrangement, but the geometry was an issue. 90 deg didn't seem possible.

I had suspected that the easiest way to get a stereoscopic wide field of vision is to use the prism concept to allow the eyes to look at two different displays. Then, compensate for chromatic problems caused by the prism by using image processing to shift two of the colors so they all align. Well, it is easy optically. I don't know how hard it is to shift those colors on the display. I suppose that a similar approach can be used for any lens color issues. Remember that we are only shifting 3 precise colors, not a continuous spectrum.

I tried to use realistic refraction index, and make a theoretical prism with a 90 Deg field of vision looking at a 4" diagonal screen. I realize the display will certainly be too close to the eye to focus on. Ordinary reading glasses should be able to compensate.

I was able to lay out the geometry successfully, but, things certainly were tight. My past efforts with a mirror were even worse and I could not obtain anything near a 90 Deg field of vision.

Has ANY product successfully obtained more than 90 Deg field of vision?

Joe Dunfee

I'll post a thread just for this but if anyone hear knows, I was wondering what the smallest image these laser pico's are able to do and still be in focus ?

This one list 15 inches in the specs. but is it true ? I thought the laser projectors could focus at any distance ?
http://www.aaxatech.com/products/l1_las ... jector.htm

And this one list 6 inches but once again is this truly the smallest it can produce and still be in focus ?
http://www.microvision.com/showwx/specs.html

If any one knows for shure what the smallest image is please post it.
It would be good information to know for HMD mods ..Thanks

Okta, it's been awhile what have you been up too! Hows the mono HMD going, are you still using it or messing with other ideas?

I mounted a Pico to a gun and are still in testing mode, was thinking of getting vitro's 4.8 lcd, was either gonna do 2 and try the leep on the cheap or try 3 wide but im thinking that will be an overkill.
Im like you, I want a wide FOV, I want to feel like im almost in there, don't care at the moment if it's not 3D, I'd rather play with my eye's relaxed for awhile then have them strain like when using the ANA glasses.
I don't use much else for 3d right now. So I want to try a setup somewhat to what I tried with the welding helmet but with a bigger LCD like what you were doing with the 7inch screen.
First where is a good place to get that meccano stuff u were using for brackets? I've seen some used stuff on ebay but thats it. If I can get what the MRG2.2 was trying to do without the huge weight and strain then I'll be happy. Im gonna get Vitro's 8.4 lcd 800x600 which should be fine for starters.

Ltr..

Heya. I haven't been up to much with this, still waiting and mulling over ideas. The meccano i got off ebay which it looks like was a great deal, i think it may be replica stuff i dont know. Be aware though that my setup is hell heavy, i have a 1.25gk plate on the back just to balance it

hi.
First of all forgive my bad english

I suggest you to use a simple and light bike helmet and work whit forex sheets...this is the most light, durable and simple material to use...plus, you can warm it and bend the sheets as you wish.

I'm working on something similiar but what i'm tryin'to understand is the LCD distance...so i have one question:

As far as i know we can focus objects there are at least 25cm from human eyes : is that value decreases using magnifiers lenses?

Thanks in advance for the reply

Yes, the use of magnifying lenses will allow a person to focus on objects closer than they normally would.

There is also a benefit for people who are be able to focus on the screen that close. Your eyes are used to adjusting its own lens a certain amount for things at a specific distance. If you are trying to trick the eye into thinking something is 20 feet away, but require it to focus on something half a foot away, there is a inconsistency. A magnifying lens makes the eye focus as though the object were further away than it really is.

For those of us who have cross the line into middle-age, a magnifying lens is a must for reading. Our eyes have lost the ability to focus on things that are near by. This gets worse as we get older.

Joe Dunfee

thanks for the info cadcoke5 : Very helpful...

So now i can continue my project...if someone have suggestion regarding lenses etc this would be the right topic!