I’ll make this quick (for those who TL;DR): the Wearality Sky is probably not what you think it is. Now, you’ve probably heard a few things about it. They’re lenses that should give you a wide FOV for VR. They should be amazing and show off the potential unlocked when you get away from something that feels more like looking through binoculars. They should have pristine clarity and image quality… And, well, they don’t.

I had received my pair a while ago. In fact, I got it before I pre-ordered the GVR3 (consumer Gear VR, code-named GVR3). At that time, I didn’t have an appropriate phone to use it with yet. Now I do. I bought the S6 Edge+ to use with the Gear VR. I played with that for a while and forgot about the Sky. But now I’ve played around with the Sky a bit — but only a bit. It was not really compelling enough for me to want to use it more, or even as a replacement for the lenses in my RDK2 (Rift Developer Kit 2) or GVR3.

If you’ve kept up with reviews and impressions going deep into what these lenses actually do given a specific size of phone, you might know that you need a 7" or larger display to get the whole advertised FOV. With the 5.7" S6 Edge+, the FOV I experienced seemed to be no more than what you would get with a DK2, perhaps even lower. And given only that information, you would think that that’s fairly reasonable. All we would have to do is get a bigger display.

I don’t have a such a device to try out the wide FOV, but I’m not even motivated to do it with these lenses. Some have said that they give great clarity and image quality, but from my experience, they simply don’t, and it would be an exaggeration to say that they do. I remember when Palmer criticized fresnel lenses, and I would say those same arguments also mostly apply to the Sky. The contrast is relatively lower, annoying artifacts are present, and you do not get such a high magnification without sacrificing other aspects.

Some people have talked about seeing “light ray” artifacts when using the VDK1 and RCB prototypes (Vive Developer Kit 1 and Rift Crescent Bay, respectively). I’ve seen them as well. On the VDK1, they look more like strips of concentric circles around the lens. On the RCB, they look more like blurry streaks across the lens. But on either of those, they never stood out extremely or became distracting. They do on the Sky. Compared to either of those headsets, you could almost say that light wants to bounce all around and scatter in the Sky lenses. To illustrate what I mean, I’ve taken a few photos (excuse me for using a crappy old phone camera):

In this photo, you can clearly see the ridges of the fresnel lenses.

A bit closer.

As close as I can make it.

A lot of impressions have said that those ridges aren’t visible when you actually put on the Sky, and it would seem that the pictures suggest it’s true — that they mostly disappear as you get closer. But it’s not that simple. You can’t see the ridges themselves, as it’s just purely harder (impossible) to focus on them, but the light reflecting and refracting from them is still there, and they manifest as concentric rings of blurriness, that reflect and refract light from other parts of the display. See those slightly pink rings on that last picture? They’re there (though they don’t look exactly like that in person, of course) when you look through the lenses. It becomes even easier to see them when you’re using the device and small shifts in your head reveal to you when the stationary parts of the image — the rings — don’t change along with your view. It’s almost like the same feeling you get when you have small smudges on your glasses. This “light ray” artifact is not as pronounced in relatively lower contrast scenes. So to illustrate the effect even better, why don’t we try a higher contrast scene?

This should very clearly illustrate what the artifact looks like. It actually does not get that much better as you move closer. All that happens is that the sharpness of the rings gets blurred out — but the windshield wiper rays are still there.

This view is a bit better, although still not exactly representative of the actual visual experience.

It should be noted that if you had filled the dark parts of that scene in with brighter light, that the light which originally resulted in the rays would not disappear. It would just be disguised among stronger light. In those cases, the light rays would act more towards an effect that “kills” contrast and blurs the scene in a concentric ring pattern, rather than appear as actual rays angled like clock hands or windshield wipers from the center like you see in the two photos above.

From my impressions, I would say that the rings become more noticeable the closer you look to the edges of the lenses while wearing them, something you can’t see in the photos because I didn’t use a fisheye lens or anything fancy like that.

It would also seem that spherical aberration isn’t solved.

All in all, I think it would have been cool to experience the full FOV using a 7" or larger display, but the presence of these artifacts and aberrations have effectively killed any excitement I would have had for such an HMD using these lenses specifically. The dome projection I experienced at SIGGRAPH, which did fully encapsulate my whole FOV, demonstrated wide FOV to me a lot better, though not on an HMD (and you can read the few sentences of thoughts I had on that in my SIGGRAPH write-up on this account, if you want — if you don’t, I basically concluded that it was extremely immersive and estimated that it would be a factor that increases Presence). I’m also kind of spoiled by the relatively more clean and crisp images you get on the VDK1 and RCB, which have largely unnoticeable light ray artifacts, better contrast, little or similar amounts of chromatic aberration, and almost as good a sweet spot, with probably more magnification power.

In closing, I’ll say that these impressions do not make gospel, and should not be taken as such. I did not mean to imply anywhere that the artifacts present on these lenses are distracting when you’re immersed in an experience. Perhaps they’re not — but they’re almost immediately noticeable even in many low contrast scenes, at least to me, unlike with the VDK1 and RCB. Another thing I am certain of is that I would not use these lenses in place of any of the lenses that we’ll get with the consumer Rift and Vive. In fact, I had tried doing it with my Rift DK2, and what I found was that the Sky lenses have less magnification, as everything immediately appeared slightly smaller and with a lower FOV. That limits a few things. It is quite unfortunate that the Sky didn’t meet any of the expectations from reading the nice initial impressions that it garnered, except for maybe sweet spot and chromatic aberration. At first, I had decided not to make a write-up of this, but after seeing recent discussions where people still regarded these lenses quite highly, I felt it was appropriate to mix in some more fair empirical observations, which may or may not be taken as criticism. The Wearality Sky lenses that I received still leave much room for improvement, in my opinion. Whether or not it can actually happen is something I can not comment on.

EDIT: Upon some review, I feel that is important to know that these lenses in general are not terrible, and that this article is not intended as a review of the product. They’re certainly better than the cheap lenses you get on a standard Google Cardboard. Whether they’re better than the lenses you get on the GVR3 or RDK2 is harder to say. The sweet spot is certainly larger and offends much less the farther you get, and there is less chromatic aberration, but other things take a hit or are introduced. Simply mechanically replacing the lenses does not work and doing both that, and hacking in a different set of pre-distortions within software, would be far too much effort for me to deem it a worthwhile venture.