Yes. And also the chromatic aberration on the Aero. I think the limitations of aspherical lenses are also associated with why the Aero has an unusually small FOV as well. Fresnel supposedly handles wide angles better, which is why Pimax’s design for the 12K lenses is supposed to use aspherical in the center and fresnel in the periphery in an attempt to combine the best qualities of each lens design.
Note that fresnel is not free of distortion either. The VR rendering pipeline first renders the view on a perfectly rectangular plane, and then it has to do another step to distort the image in such a way as to counter the distortions that the lens is expected to produce. Apparently this technique works better for fresnel than it does for aspherical. The Aero, for whatever reason, struggles to correct the aberrations. I wonder whether that’s because they are just much worse or if it’s some property of them which makes them harder to correct?
From my own experience with the Pimax 8KX, I have noticed that whether or not you perceive the bad distortions people complain about depends on 3D positioning of your eyes. And where it differs from other VR headsets like the Index and Quest 2 is that it’s very sensitive to the closeness of your eyes to the lenses. There is a very specific distance your eyes have to be for things to work as intended. Otherwise you get that blurry distorted mess away from the center.
I have wondered whether eye tracking can be used to partially or completely counter this kind of effect. I think the anti-distortion profile that gets applied in that later rendering step has to assume a particular position of each eye because the distortion changes as your eye moves relative to the lens. It seems to me that eye tracking, by virtue of knowing the precise 3D position of your eyes, could be used to dynamically alter the anti-distortion profile to compensate.
This could be part of why eye tracking is a deeply integrated feature on the Aero as well as the 12K and even the PSVR2. Perhaps the Aero has released without such dynamic adjustment, but it could be in the works for future software updates.