Now you’ve heard of him observing the decisions. Valve is pretty flat. Nobody has said he worked on the optics himself. Just read his post 
He was mainly a software developer before valve, but his inside position gave him a better perspective on the choices made for lens on the HTC…
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your 64 mm are enough.
According to my last intensive experimentations on IPD, trying to match the distance between center of lenses and real IPD is wrong.
Just think about it: if you manage to have the center of the screen in the sweet spot on both eyes at the same time, both eyes will see a clear image when looking straight forward, but what happens when you are looking elsewhere? both eyes will look at a blurry zone.
The idea is to have the distance between centers of the lenses higher than you IPD.
Thus when looking at 10-20 degrees to the right, at least one eye (your right eye) will have a clear image, and even if the other will be in a more or less blurry zone, the brain will accommodate and form a clear image.
but if you know your IPD and put it on the setting, with zero offset, things should be right.
I have myself an IPD that is probably around 64mm.
in the first place I did like everyone with this kind of average IPD, I put the lenses as close as could from eachother.
it resulted into eyestrain and wrong scale.
I was in the 60-61 total IPD range (hardware IPD + offset)
But after I experimented A LOT on assetto corsa, I’m now close to 65mm with 0 to 0.5 mm pitool offset.
which means that the mechanical distance between lenses is minimum + 4.5mm
So the center of lenses are pretty far from each of my eyes when I look straight forward. do I see a blurry image? not at all.
If I increase the offset and decrease the lenses distance to achieve the same 65mm total, I will see more clear when looking straight in he middle of my FOV, but the sides will be blurry, and my eyes will be less relaxed.
also if I put an inferior total IPD, the cars will start to look like they “shrink” when they go further away from me, instead of only going away
that’s a good indicator of an IPD that is too low.
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it may vary per person, my IPD 67 & I was able to achieve 2 both eyes sweetspot & I have about 70% of large FOV clear without distortions.
I had previously one of the eyes a bit fuzzy & while I see the image clear it was completely uncomfortable for me & I always wanted to clean my eye, it just shouldn’t be this way IMO. But probably for others it’s more comfortable than for me.
Now apart of colours Im ok with Pimax optics though but it was a long way.
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Not having the sweet spot in front of your eyes will NOT give the best image, Me and many others want to see what is in front, I want to see My hands when I hold them up in front of me, or gauges in front of me, Elite dangerous, when I turn My head to the side to see the side panels it will appear in front of My head. How often do you sit sideways to your monitor and only rotate you eye to read text, It is what is in front of you that counts, this problem has been a PROBLEM ever since the HMD was released. Until they address this issue, with eye to lens adjustment and a wider IPD range, you will get people bring this problem up.
One thing I hate about the Pimax, is that trying to read directly in front, always seams like one or both the lenses need cleaning because it is slightly out of focus.
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The issue for me is that it doesn’t feels natural; Possyguset explains it quite well to:
And I do not think it’s the way it’s supposed to be because e.g. the Index has the centers of fresnel concentric rings aligned with the IPD setting.
@NextGenVR: IIRC you have a StarVR at your disposal - could you kindly check if it has the centers of fresnel concentric rings aligned with the IPD setting too ? That would be an ultra-large FoV canted-display headset too, just to cover the area if one argued that with canted displays you’d want it differently.
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My 20 to 30 hours of experimentations on different IPDs on assetto corsa, using both IPD offset and the headset wheel, (only the first, only the second and every combinations of both), has leaded me to the conclusion that putting the lenses at the minimum to match the lenses center distance to my IPD gives to a total IPD that is way bellow my 63.5-64.5 IPD. : with zero offset it gives a 60mm IPD.
at this IPD, the world scale is wrong in assetto corsa. it’s not obvious in the first place, but there is a feeling of “not really being there”.
that’s because the other cars don’t appear at the right scale when they get further away from you : they look like they rather shrink.
in addition my eyes are not really relaxed when looking at the far infinity.
Now if I use the offset to compensate and reach 64.5, I’ll have the good scale but some terrible eye strain, and the clarity will be reduced to a small circle just in front of me where both eyes see clarity, but everything else will be blurry since both eyes will look at the more blurry part of each circle.
Even if you are looking in front of you, human eyes keep moving quickly around the center of sight.
99% of the time you’re probably not looking just in the middle of your sight, so when I look at the cars on the left or on the right, it will be blurry on both eyes… I’m not speaking about looking at the extreme sides, I’m speaking about having a normal use of my eyes in a car.
Now if I limit the IPD offset to +1.5 and use the wheel to add the extra mm needed mm to reach 64.6mm, I will have the good scale, no eye strain, and the zone where I can look with acceptable clear image will be more vast.
Only one eye at a time will look at a 100% clear zone, but the area where you don’t have both eyes in a blurry zone will be way larger, which could explain the overall better experience I get.
It also looks like my brain compensate and gives me a good clarity compromise without eye strain during and after the VR experience.
I wish the lenses would give as much clarity as PSVR ones, but it is what it is, concentric circles getting more and more blurry as you look away from its center, and canted large panels.
My point is that the IPD number showed by pimax is not as wrong as it has been stated.
it is claimed in this forum that if you have a 63mm IPD, you want to set it at 60, but to me it’s wrong.
in term of scale, my experiments showed me that the IPD number is right, at least for me, and at least in assetto corsa.
And my second point is that putting the center of the lenses as close as your real IPD doen’t necessary lead to the best overall experience, cause it will limite the clarity zone to a small circle just in front of your eyes while everything else will be blurry, and then the Offset needed to reach your real IPD will be too high and will lead to eye strain.
the experience may differ from someone to someone else though.
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I already have shown you the explanation why the default IPD is wrong for other ppls - it’s coz of difference in eye relief (distance between your eyes, your skul & the HMD)
This post has really nice images that illustrate the reason with text explanation.
https://community.openmr.ai/t/clarifying-near-ipd-x-distant-ipd-confusion/14809
But seems you neglect the point in there.
I wonder when you experimented with your IPDs did you simultanously try to change HMD tilting & eye relief values?
In my case tilting significantly affects the side clarity & helps with distortions
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indeed during my experimentations, one of the last thing I did is to put back the forehead part of the comfort kit that I removed (I cut the foam of my comfort kit into different pieces to mod it) to have my eyes closer to the lenses (and maximise the FOV)
But when reaching 65mm IPD it leaded to some discomfort.
with the forehead foam back on, my eyes where a bit further away from the lenses but it was better, so yes eye to lenses distance counts, but still, if I try to put the lenses as close to eachother as possible and keep the offset at zero, which makes an IPD of 60 instead of my 63.5-64.5 far IPD, the scale and sens of being there will be off.
if I move the wheel and play with the IPD offset, and reach my real IPD, things get on scale.
I also have to tilt the headset a bit to have a clear view.
here is my mod :
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also for some people it never will be possible to put their eyeballs as close to the lenses as some other users may do even if they will put off the bracket, coz browns & skull will be in place, so until you get a chainsaw & shape your face or do some other hardware tweaks like lenses cut to bypass your browns bones you will always have bigger eye relief value than other user.
So I would say goggle-eyed people will have bigger % of change to succeed with Pimax
Wholy cr… that CK foam looks might worn :S how long have you been using it ?
“sorry off topic”
about 2 months. it has been quite warm those last weeks/months, so I guess this is what sweat does to the foam
a good wash is probably welcome, isn’t it?
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My Index has those centres 2-3mm wider apart than the reported IPD, which seems consistent with the 5+5 degree canting.
Even with that offset; With my low brow preventing me from cutting eye relief as low as it should be, I need to part the lenses farther yet, to get into the sweet spot, where the view through the lenses is sharp all the way to the edges, and nothing is distorted.
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Yep, I know this eye-strain all too well.
In theory it may be right. But as a matter of fact, when you actually do want to focus on something, it is natural to look straight at it, i.e. have it in the center of your sight. But everytime I do this with the 8KX it is slightly blurry on both eyes, because non of them are in the small 100% sweet spot. So I have to then move my head artificially to move the object I am trying to focus on some 5-10° to the left or right. At that time it will become sharper because it will be in the sweet spot of one of my eyes. Still, it is not perfect because the other eye reports it to be slightly blurry.
This is a disturbing sensation to me.
But I believe the issue of not feeling the IPD to be set correctly is a greater issue for me than the above issue. That one so far has prevented me from really enjoying the 8KX.
Apart from that the number of games not properly working with both Pimax headsets but also sometimes Index controllers is really annoying. In an ideal world the Pimax Experience would be able to correct such issues with the apps and load & apply suitable Index controller profiles upon request. But I guess that is a rather big ask…
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