I like the Pimax lenses. They’re clear, and have little god rays. There’s just one thing. The sweet spot is too close to the center of the lens, when it should be more towards the inner edges of the lens. This would allow users to have better focus when viewing close objects. I’m sure some of us would probably pay 200-300 dollars for a better pair of lenses that had a sweet spot like this.
We know that replacing the Pimax lenses is not especially difficult. You can remove them with a suction cup. There’s also a layer between the lens and screen, which would make replacing lenses even safer. I really think Pimax should consider doing this if possible. Are there any plans for better replacement lenses of any sort? @PimaxUSA@PimaxVR
It is not that the lens centres should be closer together; Their positions are as dictated by the canting. -It is that more of the lenses - as much as all of them as possible, should be focussing on the screen to begin with, so that you don’t need to push them closer together.
Getting the fundamentals right must be alpha and omega - do the difficult engineering first; Dropping in higher specs components is the “easy” part.
It would also be good if one could be rid of the partial, and smoothly blending convex part on the viewer side of the lens: The transition constitutes an optical complication, as well as a “downward slope”, where, unless you’ve got a lot of eye relief, your gaze meets the surface of the lens at a very obtuse angle - almost tangentially.
EDIT: No #!%* fresnels at all would be preferrable - /me detest them, but I can understand why one migh choose them. :7
Personally I don’t mind the fresnel lenses a ton since Pimax actually did a pretty good job at keeping godrays and rings low. It’s mostly just the sweetspot location that is a bit annoying. Though if they can do aspherical that’d be pretty awesome. Wouldn’t aspherical lenses be heavy for such big lenses?
Depends, I guess. For such strong lenses, they would need to be thick, but they would still be made out of the same plastic, which is lighter than glass.
The reason fresnels are used is mainly about a thinner lens producing less distortion when one look through it off-axis – not so much about weight. (They also produce just as much chromatic abberration as a conventional lens of the same material, to quell another common misconception. :7)
As for aspheric: I am a bit doubtful about their benefits in a VR headset, over a simple lens – seems to me their tapering toward the rim is the cause of the sorts of distortions that bother me, rather than the fix.
TL;DR - Don’t expect new lenses for any existing headsets or any upcoming headsets in the near future.
There are multiple issues with making a new set of lenses, with the foremost being the cost/reliability. IIRC they claimed to have gone through 7-8 iterations of the lenses for the 8K, with a retooling cost of ~$50000 per iteration, and ultimately settled on the current lenses. As you can see, there would need to be a LOT of interest in the alternative lenses to even consider it.
Then there are the additional costs and complexity of making/upkeeping alternative distortion algorithms for ALL their headsets (excluding the 4K). They will have to add an option to Pitool to manually select your lens type, since the headsets aren’t designed with a way to detect it, and there will inevitably be about 50 bajillion tickets/forum complaints by people using the wrong setting.
If it works well, then everyone that currently has a headset will complain that they didn’t get it. If it doesn’t work well, then everyone who bought one will complain and they probably won’t sell enough to break even. Of course, it could be a split decision since there are ALWAYS compromises for lenses. Do you want better god rays, distortions, cost, weight, etc… because you can’t have all of them. The current lenses are the compromise Pimax has settled on and I sincerely doubt we are going to see a new set of lenses until Pimax overhauls their headset design.
Just understand first that the frensel lenses were specifically designed to minimise some dynamic distortions that we know can cause discomfort and motion sickness. The frensel lenses were not selected for low mass, low cost, hiding subpixel structure, filling SDE or any of the other crazy conspiracy theories I have read. They were the only practical lens technology for hitting the overall set of optimisations we wanted, especially minimising eye-position dependent distortion with a single element. They are not “cheap” lenses and need special equipment to make well. They are lower mass than the “equivalent” non-frensel profile lens, but that is mostly a happy coincidence, if a conventional lens could achieve the same performance in the axes we care about we’d happily tolerate the small mass increase for the reduced stray light and easier moulding. Our goal was to have lenses that worked well for everyone, from the least sensitive to the most easily nauseated. Some people just don’t perceive pupil swim, at least not until you tell them what to look for, and some people once they see it can’t unsee it and it ruins all HMDs with swimmy optics forever for them. Most concerning is that swimmy HMDs cause nausea at an almost subconscious level, you don’t need to perceive it for it to make your experience using the HMD unpleasant.
as far as I got it, it’s one of the ppl who worked in Valve on Index HMD
It’s for sure not about Pimax, their lenses make sick almost everybody if not positioned right, so I guess it’s better than non fresnel ones but still they did something wrong there.
I will say, though… I am curious what the unholy contraption above would look like, had I matching cameras and distortion compensation to go with it, because those 74mm diameter glass lenses would need huge screens, set into a big bulky box, to fill their FOV (140x140mm panels, for 180x130-ish degrees left and right combined), and since the p8kX panels are not by far that large, that means 4k over a much smaller, letterbox-like FOV – would love to see what the resulting resolution would look like (I dunno - something like 30-40 PPD).
(Oh, and: Hardly any glare. :9)
( EDIT: I mean, I do get the resolution in question, as it is, but the frames are not rendered for it, so they just show up smaller, instead of at the right scale, and with more detail.)
I still am waiting for full fov (including erasing the nose). Have been since Kickstarter actually been asking lol. I’m not sure how they’re NOT interested in this. They’ve literally touched up on every original feature of pimax except the fov. The fov IS pimax.
