Interesting 'FIX' to the PIMAX Eyestrain problem

Source: https://www.reddit.com/r/Pimax/comments/ewab3l/extreme_ipd_mod_done_no_more_eyestrain/

Maybe I should try this

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He says when he measured the actual ipd on the headset at the lowest setting he got a result of 70mm, is it possible?
I also have 64 and I also set it at the lowest setting and -2 by software

X9Kw0rF_d

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Well when I set at 62 and my IRL IPD is around 67 the world scale is off - way to big cars interia or cokpits planes/ships.

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We want to invite @risa2000 to this discussio.

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Also interested to know how this turns out. Anything that makes a difference is worth knowing about, although I have definitely had the most eyestrain from resolution issues rather than IPD.

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I’ll also offer an alternative to this discussion by pointing out my IPD is the same as the Redditor’s and at first I had eye strain in the Pimax and used smaller IPD’s as a way to try and use it but now I use a manual adjustment of 64mm in the Pimax with zero offset after having adjusted and feel more comfortable than ever.

I believe for some people there may be an adjustment period adapting to the canted lens design but ultimate the best IPD to use with the Pimax is the one that matches your own physical measurement.

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There is indeed an adjustment period to everything about VR headsets. The way the eyes focus, the IPD, alignment with the optical axis, etc. The Pimax Vision 8kX looks at least 50% clearer to me than when I first started seeing it at CES, with no significant change in any relevant settings, and it is looking sharper all the time.

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I wiped the lens of my 5k+ last night and it was immediately 200% sharper and clearer.

I couldn’t help myself.

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He did not measure the IPD on the headset, just the distance between the lens centers. The discrepancy between the two is by design (Clarifying Near IPD x Distant IPD confusion).

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You can try to set the hardware IPD to 62 and then compensate by the software IPD offset back to 67. This should preserve the geometry (scale) by keeping the virtual cameras at 67 mm distance, while allowing you having the lenses physically closer.

You may suffer the distortion because the eye will no longer be on the optical axis of the lens, but it is worth the try.

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I remember that post, although if the minium of the lenses is 70, and I have 64, and I’m looking at a near object it’s not possible to set it right.
The distortion profile or the render itself should compensate the canted design. Right?
Does this theory applies when PP is activated as well? I feel a bit more comfortable when PP is activated, even if the game don’t require it.

Since it is designed this way (to have discrepancy between the two measures) you should be able to set the headset “right” with your IPD.

On the other hand, setting it “right” the intended way does not guarantee that it will be comfortable or even acceptable for you, as already proved by some other users here.

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This is how I think the render of a canted displays should work, and how the Pimax distortion profile actually works. If not it can be adjusted by software ipd

The alignment of the eyes should not follow the surface of the displays

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Can you point me to were it has been confirmed your theory has been confirmed by Robin ?
Do we even know if these lenses are Linear or spot lenses ?

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Same here and still eyestrain. This is crazy that physical IPD adjustment is so off! Has this been fixed in new models??

What is the way to fix this? Is this something pimax could fix with a design/engineering change (and still keep canted displays?) Also I have an index and I do not have eyestrain issue at all with its canted displays why?

StarVR One seem to be the only unit I know where they managed to solve IPD adjustment. Granted, Lionel Anton and team had more years to perfect this and he is the one who created the modern canted Wide FOV and now utilize eye tracking adjustment. Although i have experience with canted headsets for few years back in 2013, indeed there is plenty variables when dealing with, distortion profiles, lens augmentation/ distance of the display to the lenses, quality of lenses, physical position of the lenses and appropriate software calculation to match the physical hardware.

If you wear the Index perfectly fitted (…and this means finding a tiiiny sweet spot, I’ll admit), you should have pretty clear imagery almost all the way out to the edges – the two-lens sandwich per eye seem to “flatten the field”, so that focus does not fall off as drastically, away from the centre, as we are used to. Because of this, there is no need to do any tradeoff trick with too low lens spacing, which messes up distortion correction, and you are free to look around, without things going out of focus. (The canting is also only half that of the p8k/5k.)

(EDIT2: …and that is of course the correct way of dealing with the issue; Make an optical solution that puts the entire FOV in focus. There are reasons there was disappointment the new Pimax models still use the same lenses. (…at least until we get lightfield displays, which moots the focus matter somewhat :7))

Now, if you want to experience eyestrain anyway, with Index and P8k/5k both; Try some titles that have advanced shaders that still come out wrong, producing strong binocular rivalry, even when rendering in parallel projections mode – some facing vectors still do not line up – this is typically wherever you have reflectivity; Raytracing can’t come soon enough. I can e.g. barely look at the waves in “Age of Sail”, or the wall panels in “Blade Runner 9732” (EDIT3: those last appear to have parallax mapping, too, but that effect seems to work fine, there). (EDIT: I launched “Titanic, Honour and Glory” demo 3 yesterday, after somebody mentioned it, which reminded me I hadn’t tried it in my Index, and all the cubemap reflections and refractions look terrible – I don’t recall whether they were quite that bad when I had previously gone there with parallel views headsets, but envmap reflections are of course always going to be way off under any circumstances; Again: Raytracing can’t come soon enough. :9)

Now, we have a few members of this forum, who claim they do get edge-to-edge clarity with their p8k/5k, which would mean they are fine and dandy, without ever needing any lens-spacing trickery, and I would really like to know what makes things that way for them, and not the rest of us. :7

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No. In fact Pimax never confirmed anything even when I asked direct questions. You may have a better luck though.

What do you mean by “linear” and “spot” lenses?

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So its just a theory, and I have no chance pimax is going to answer me if they will not answer you :slight_smile:

There are basically two types of Fresnel lenses . One is the Spot Fresnel lens and the other is the Linear Fresnel lens . The spot Fresnel lens focuses the light onto a spot and the linear Fresnel lens focuses light onto a line. its the way the rings are cut into the lens.
When I say line, is a small line slightly wider than a spot. and dose not imply a line across the hole lens.

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