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Actual amount of pixels used in all current VR headsets

redguy113redguy113 Posts: 1
NerveGear

This is in my opinion an interesting an overlooked by the general public conversation about the actual resolution of modern VR headsets. All of them seem to list the resolution of the LCD or LED screen used but I think its misleading for two reasons:

1) Left and right images for each eye are overlayed, like our eyes do in real life. Doesn't this mean its not fair to say for example with Vive each eye uses half of the screen which is 1080 x 1200 pixels. is it fair to say horizontal res is 1080 if the right edge of the left eye screen and the left edge of the right eye screen overlay and our brain merges them like real life? Does anyone know the rough amount of screen area that our eyes overlay so we can have a rough number of the "actual" resolution per eye?

2) All of the pixels inside the rectangular area are not used by the lenses and in some programs or games the edges are just black while other dont bother putting a stencil on the rendered image. I've read that black area is about 27% of the screen which , correct me if I'm wrong, is makes the actually used horizontal pixel count used by the headset closer to 720 than even 1080.

And this other question is not related to the topic title but why do the lenses seem to distribute the pixels equally when our peripheral vision naturally is more blurry and sees less detail? If I recall the lenses are custom shaped fresnel lenses so I don't know how hard it would be to stretch/zoom pixels on the very edges of the peripheral vision and LED screens to decrease the tunnel vision effect.

Also unrelated. but why is LCD/LED panel PPI even used for VR specs when you are watching the screen through a zooming lens? This also sounds like cheap ass marketing at worst and a rule of thumb measure that doesnt tell anything other than which headset likely has less screendoor effect at best.


Comments

  • RoasterRoaster Posts: 797
    Neo
    When looking at an image in the headset (holding your head still) you are free to look around, so it's desirable to have the full field in focus and undistorted.  Distortion due to the lens type is often counteracted in warping the image to suit, as well as chromatic aberration correction.
    If you assume the designers are doing the best they can, they use as much of the screen area as possible, and there will be vignetting so the corners are cut off. Typical rule is that the area of a circle inside a square is .785 times the square area. Various screens can be compared in the sense that the best you can do will look better on a screen with a higher resolution.  The designers have a choice in how much magnification to use, which gives a trade off in FOV vs SDE.
    I'm not sure the effect of a small screen vs a large screen with the same resolution, but the small screen may give a flatter field when magnified with a simple lens. PPI is kind of irrelevant, unless it contributes to the dead space between pixels. Also RGB vs Pentile arrangement is important to the image quality, and can lead to misleading claims for actual resolution.
    Screen resolution per eye is the most honest way of comparing units. In the end you take what they give you, so compare units to see which is best for you. It will probably be different for people who wear glasses.
    Not too long ago the best you could do was 2D 800 x 600 with no tracking, for $1k.
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