From Pimax Berlin meetup in Sept 2018Pimax 8K M2 & 5K+ Impressions
Recently I got a chance to spend some time with Pimax 8K M2 and the new 5K Plus units. Here are some impressions. The good thing is that they actually let us choose games from SteamVR library, so we can see how the hardware actually works and not some carefully polished and prepared demos.
Let’s begin with the image quality. The image was certainly best I’ve seen in any headset, outclassing Vive Pro, Samsung Odyssey. What helps is full RGB subpixel matrix. The image quality was very comparable on 8K and 5K+. The SDE and pixels are visible on the 5K+ if you try hard, but practically invisible on the 8K. On the other hand the 8K image is upscaled from 5K source, so the additional pixels are not used anyhow. In fact, the image is a lit blurred because of that. Still i believe the quality is slightly better on the 8K. For me the observed FOV was around 170 (+/-) horizontal, which would mean around 145 per eye. That means some 26 pixels per degree for 8K and 17ppd for 5K. For comparison, Vive Pro has about 16ppd, but pentile matrix. Some time ago a wrote an article about SDE and limits of human eye, the Pimax is still not there (yet).
Optics and disortions
One the of the key challenges for wide FOV headsets are the optics and especially eliminate the distortions around periphery. Pimax does this quite well. When i looked carefully there was indeed a distortion at the periphery, but a guess i would estimate the objects shifted about 5-10 degrees. It was not anyhow disturbing during game play and I wouldn’t notice if i wasn’t looking. The problem can be also with content — traditionally, you cannot render more FOV than 180deg. While this can be bypassed by rendering multiple images or using tech like Lens Matched Shading from Nvidia, it also needs to be supported in the game. For instance, Unreal Engine added support for angled panels in October 2017, not sure about SteamVR support. While new games might work with angled displays correctly, older games might never support wide FOV without distortions.
The headset is very light and comfortable to wear, it’s lighter than Vive and more certainly more comfortable. It’s certainly bigger to accommodate the screens and lenses, which comes with a plausible side effect — there is more space for glass than on Vive! There was one person on the meetup with glasses and had no problem taking the headset on. IPD is adjustable to 70mm, which is same as Rift (Vive IPD slider can go slightly higher).
Like I said at start, they let us play from a SteamVR library, so we can see how normal games behave with Pimax 8K and not some carefully prepared demos. It’s good to know that SteamVR games works. However, with Pimax you can see much more details, and therefore notice all lower resolution textures or lowpoly models. It can be distracting, because the developers got away with on Vive or Rift, but now on Pimax it can ruin the magic. What looked real, not looks fake.
They told us that 8K is a little more demanding in HW (not sure why, since the image on the 8K is just upscaled from 5K), and that they recommend 1080Ti or at least regular 1080 for 8K. 5K might work with 1070, but 1080 is recommended. For 8KX, next gen graphics card will be required.