Kopin is touting a new prototype VR headset featuring their 4K OLED ‘Lightning’ microdisplay that they say is made specifically for VR. At nearly half the size of other headsets, and made from lightweight materials, the device feels featherlight compared to VR products on the market today.

Update (8/19/17): Following my hands-on with Kopin’s ‘Elf’ headset at E3 where I got to look at the form-factor, I recently met with the company at the Silicon Valley offices of Goertek—Kopin’s manufacturing partner—to get a look inside a working demo of the headset.

Side and Weight

The functional Elf headset prototype was the same impressively small form-factor as I saw previously, featuring a pair of Kopin’s 1-inch ‘Lightning’ displays each with a 2,048 x 2,048 resolution and 120Hz refresh rate. The headset isn’t just significantly more compact than others—at just 220 grams it’s less than half the weight of the Rift and Vive (though at this point it’s lacking integrated audio, IPD adjustment, or positional tracking tech, which would require additional hardware and weight).

Connection

The headset connected to the host PC with DisplayPort and USB plugs which came together into a single thin cable that plugs into the headset with a USB-C connector. Kopin has developed an OpenVR driver to allow the headset to operate with SteamVR content.

Dark (for now)

The demo I was shown through the Elf prototype was a SteamVR game called InMind 2 VR. In the demo I was looking at models of brain neurons. The first thing I noticed when I put on the headset was how dark the image was. I could see fine, but it definitely seemed darker than it should be. When I asked Kopin about this they said that the display isn’t finalized and they expect to double the brightness by the time they are manufacturing them for sale.

Field of View

The second thing I noticed was the field of view which felt much closer to Google’s Daydream headsets than what you’d be used to with the Rift, Vive, or PSVR. Kopin said the prototype I was looking through was a 70 degree field of view, and that they’re working on developing different lenses to offer 80 and 100 degree fields of view (and I got to look through early versions of those lenses; more on that later). On the 70 degree prototype, the ‘binocular’ feeling (of having very noticeable dark circles around your field of view) was quite apparent. Despite the incredibly smooth and sharp image I was seeing, the low field of view is an immersion killer so it’s a good thing that Kopin is also developing lenses with a wider view.

Image Fidelity

With more than three times the pixels than the Rift and Vive (2,048 x 2,048 vs. 1,080 x 1,200), it looked stunningly sharp (pixel density in this case is getting an extra boost from the lower field of view too). Individual pixels are all but invisible, and I couldn’t make out any screen door effect. Since the 70 degree FoV lens isn’t Fresnel, I didn’t see any god ray artifacts (which are prevalent on the Rift and Vive), nor did I spot any chromatic aberration. I didn’t see any obvious mura issues which is good, but would want more time in the headset to be sure that there is none. Also, because this is a micro OLED display, the blacks were very deep. However, I didn’t get a chance to see the right scene to assess whether or not there was any black-smearing present.

Distortion and Correction

The Elf headset is made entirely to show off the display and lenses, so right now there’s no positional tracking tech built in. That means that in my demo the headset was only tracking rotation. The tracking felt fine and seemed exceptionally ‘smooth’ (likely thanks to the 120Hz refresh rate) though as I turned my head I noticed quite a bit of distortion warping the view around the periphery which seemed to be due to the lenses. Kopin says they are still working on the driver for the headset and tweaking the distortion correction; they seem confident that once the lenses and driver are finalized they’ll be able to eliminate the warping.

The Cost of a Wider Field of View

I also got to see prototype versions of Kopin’s 80 and 100 degree field of view lenses (backed by the same Lightning display) which were hooked up to a test board rather than built into a headset. The 80 degree lens was a two-element Fresnel and was much brighter than the 70 degree or 100 degree. It was clear that the field of view on the 80 was wider, but since it wasn’t hooked up to a headset with headtracking, it was difficult to get a good sense for how immersive it could feel.

The 100 degree lens was a two-element non-Fresnel and it was dark like the 70 degree lens. Although the lens itself may provide a 100 degree field of view, at that field of view you can see the edges of the display which, in my opinion, is less immersive than having a smaller field of view where you can’t see the edges of the display.

Kopin plans to develop larger displays in the future, which could mean a larger field of view without visible edges, but they won’t be ready for several years yet. Given that, Kopin’s 80 degree field of view option seems to be the best sweet spot presently for immersion and image fidelity. The big question will be: to what extent are consumers willing to trade field of view for image fidelity?

Elf is a Pitch, Not a Product

One important thing to remember about all of the above is that Elf headset is not going to become a product, it’s simply a pitch for Kopin’s VR microdisplays and Goertek’s manufacturing capabilities. The company’s hope is that a consumer electronics company will want to produce a product based on the Lightning display, and the Elf headset is the demo to sell them on the form-factor that it enables. Goertek says that the companies are “actively marketing” the Elf headset to potential consumer electronics companies. That means that an end product containing Kopin’s Lightning display might end up looking quite a bit different than the Elf headset today. In fact, although Elf is tethered, Kopin says that the foundation of the headset is also suitable for all-in-one mobile VR headsets.

The original article continues below, which speaks to Kopin’s long term plans for developing VR displays (including those of higher resolution and large size), and the microdisplay vs. traditional approach to VR displays.