Hands-on LetinAR optical system – The Ghost Howls

At AWE US, I have been able to go hands-on with the newest LetinAR optical system for AR glasses. In the following, you can find my impressions!

LetinAR optical system

It is not the first time I have gone hands-on with LetinAR. I had already met the company two years ago, always at AWE US, so I am quite familiar with its product. The idea behind LetinAR is to offer a display system for AR glasses and smart glasses that use micromirrors. You have a transparent lens that lets you see the real world in front of you, and then on the lens, you have some tiny mirrors that reflect into your eyes the image of the virtual elements projected by a light emitter (basically a display). Theoretically, since the mirrors are very tiny, you don’t notice them, as you don’t notice the eyelashes that you have in front of your eyes. And theoretically, the little pieces of the virtual image reflected by all the single micromirrors compose into a single cohesive image onto your eyes. The result is so augmented reality, with the view of the real world and then some virtual elements imposed on top of it.

LetinAR claims that this approach can offer many advantages, for instance:

• The lens can be very transparent, and not darkened out like it happens with glasses like HoloLens or XREAL. This also means that you can see better the eyes of the people that are in front of you, for a more human connection

• The optical system is very simple and does not require many components (the lenses require manufacturing with all the micromirrors, though)

• The power consumption is pretty low, which is very important for standalone AR glasses

I have been shown all the advantages of this system in a presentation. You can read them too on this page, if you want to go further.

LetinAR has many variants of its optical system, each one of them with its advantages and disadvantages. I have been told that its optical systems can be used for the whole gamut of see-through devices, from smart glasses to AR glasses.

Notice that the company does not aim at building its own glasses, but at providing its technology to other manufacturers. In fact, I remember last year I tried at the Qualcomm booth some Japanese AR glasses whose optical engine was provided by LetinAR.

LetinAR hands-on

When I tried a prototype of the LetinAR system a couple of years ago, I found it promising, but I also found that the system was not always working as expected. The first prototype I tried was made with pinholes, that is, tiny circular mirrors, and I found that sometimes I could still see the halo of the holes, but at least the colors were bright. Then I tried a new evolution of the system, with semitransparent little “mirror bars” and found that the image was a bit less bright than the first model.

Fast forward two years, what was the “new evolution of the system” is actually the current technology: I was given some glass frames with the LetinAR system inside, and I could grab it and take it close to my eyes using my hand to enjoy augmented reality. The eye module clearly featured some horizontal little lines, which were the semitransparent mirrors.

The first test I was provided with was a static image, as if the glasses were used to provide a virtual display, a la XREAL One. I was positively surprised by the image quality: the resolution was good and the colors were very bright. The problems of the image being a bit transparent and washed out a couple of years ago had totally disappeared. The field of view was also pretty ok for the current status of augmented reality: I have been told it was around 45°. As for the image consistency, it was pretty good, as you can see from the through-the-lens picture, but still, I could notice some dark-ish horizontal halos of the mirrors. In certain conditions, I could see the image, but also some gray-ish horizontal lines superimposed on it. These were for sure artifacts created by the horizontal semitransparent mirrors, whose reflections did not combine into a single cohesive image.

After this demo, the LetinAR representative also let me try something related to augmented reality, so we started a new demo that showed me some 3D cubes floating in the air at a distance of about 3 meters from me. What was cool about this demo was that at that moment, all the visual artifacts disappeared from my view. It was like black magic: no more gray lines, and I could just see a cohesive, bright 3D augmented reality application. But how was that possible? Well, there are a couple of things that contributed to this “miracle”. One is that my eyes started to get used to the visual system, so my brain started to ignore the grey lines. The second is that while the 2D image of the first demo forced me to focus on a close distance, the AR demo let me focus on more distant elements, so all the disturbances close to my eyes became more blurred and unnoticeable.

It was pretty cool because for the first time, I could see what the final goal of LetinAR is: I’ve seen all these tiny mirrors disappear and just give me pure AR.

One more thing

The company showed me the roadmap for the next months, and there are pretty cool things coming. I can not share the details, but two things they are working on are improving the field of view and also making the “lines” less noticeable from the outside. Currently, if you wear some LetinAR lenses, you see the eyes of the wearer with some bright lines in front of them… which is very cyberpunk, but not very natural. So the company is trying its best to let you clearly see the eyes of the person with the glasses you have in front of you.

Final impressions

I came out with a good impression from the LetinAR demo. You know me: when I see progress, I’m always happy. And I’ve seen that in these two years, the company improved its technology, creating glasses with a decent field of view and bright colors. And in some conditions, I have even seen all the artifacts disappearing, which was mindblowing to me.

Of course, there is still some work to do: the FOV should be larger, and especially, the artifacts should always disappear, not only in some conditions. They should disappear both from inside the lenses (for the user) and outside the lenses (for the people looking at the user). The company showed me they are working on all of this, so I can’t wait to try the next model that is coming in the future.

Related