Android Virtual Reality help

[PTOWN GAMER]

Hi everyone.

I’m just about to order a VR headset for android.

The problem is the FOV.

It’s confusing me. Different headsets have different FOV. So which one would be best? 90, 100, 110,180??

Second question is:
I have the var's VR Video Player app.
Now when I play a video it has this slider on the right side which goes from 140 to 0.
It’s an inbuilt FOV thingy.

What is the best setting to put that at?? 90, 100, 110, 120, 130, 140???

So please can someone give me a Combination of headset FOV + software FOV for the most real experience?

Thanks

 

[Solandri]

Field of view (actually angle of view) depends on the width of the display, and the distance from your eyes (or apparent distance if the VR set uses lenses). Your preference is personal. A wide FOV is more immersive, but the pixels appear larger due to the higher magnification.

As for the software FOV setting, you want to set it to match the hardware FOV. The hardware FOV won't be exactly what the specs say - it depends on the (apparent) distance from your eyes to the display. So it will vary slightly with the shape of your head and how the headset fits to your face.

Sit in a fixed location (i.e. not on a sofa where you can slide around). While wearing the headset, remember where the left and right edges of the image are. Quickly remove the headset and note the places on your walls where the left and right edges were. This may be easier if you turn your head slightly so one of the edges line up with a corner of the room. Then you only have to remember the location of the other edge on the wall.

Now grab a protractor and set it approximately where your eyes were. Measure the angle between the two spots on the wall. That is what you should use for your software FOV for the most realistic experience.

Please note that depending on the application, you may want to select a wider software FOV. e.g. In a FPS, having a wide view may be more important than the view being realistic. Just be aware that a mismatch between the FOV setting and the actual FOV of the image can cause headaches or motion sickness. (Usually it's not a problem though. It's rarely noticed in movies, even though there is only one "sweet spot" in the theater where the image is absolutely correct.)

Trivia: this mismatch between the actual FOV and the image FOV is what makes wide-angle photos appear distorted. If you put your nose up to the monitor so the FOV captured in the photo matches the FOV your eyes are actually seeing, the image will not appear distorted.
https://danielteolijr.files.wordpress.com/2015/04/march-of-the-zombies-copyright-2012-dnaiel-d-teoli-jr.jpg

 

[PTOWN GAMER]

Field of view (actually angle of view) depends on the width of the display, and the distance from your eyes (or apparent distance if the VR set uses lenses). Your preference is personal. A wide FOV is more immersive, but the pixels appear larger due to the higher magnification.

As for the software FOV setting, you want to set it to match the hardware FOV. The hardware FOV won't be exactly what the specs say - it depends on the (apparent) distance from your eyes to the display. So it will vary slightly with the shape of your head and how the headset fits to your face.

Sit in a fixed location (i.e. not on a sofa where you can slide around). While wearing the headset, remember where the left and right edges of the image are. Quickly remove the headset and note the places on your walls where the left and right edges were. This may be easier if you turn your head slightly so one of the edges line up with a corner of the room. Then you only have to remember the location of the other edge on the wall.

Now grab a protractor and set it approximately where your eyes were. Measure the angle between the two spots on the wall. That is what you should use for your software FOV for the most realistic experience.

Please note that depending on the application, you may want to select a wider software FOV. e.g. In a FPS, having a wide view may be more important than the view being realistic. Just be aware that a mismatch between the FOV setting and the actual FOV of the image can cause headaches or motion sickness. (Usually it's not a problem though. It's rarely noticed in movies, even though there is only one "sweet spot" in the theater where the image is absolutely correct.)

Trivia: this mismatch between the actual FOV and the image FOV is what makes wide-angle photos appear distorted. If you put your nose up to the monitor so the FOV captured in the photo matches the FOV your eyes are actually seeing, the image will not appear distorted.
https://danielteolijr.files.wordpress.com/2015/04/march-of-the-zombies-copyright-2012-dnaiel-d-teoli-jr.jpg

So if i want less pixels i should go with less wide hardware?
So what do you think is the sweet spot for the hardware, 100, 120?

 

[Solandri]

So if i want less pixels i should go with less wide hardware?

For a given resolution screen, if you want higher pixel density (the pixels look smaller), then you should go with the narrower FOV.

So what do you think is the sweet spot for the hardware, 100, 120?

Well, nothing presently hits the sweet spot. 20/20 vision is defined as the ability to distinguish a line pair with one arc-minute of separation (2 pixels basically). So to fool an eye with 20/20 vision, a 100 degree wide horizontal FOV VR system would need 100 deg * 60 arc-min/deg * 2 pixels/arc-min = 12,000 pixels horizontal resolution.

Nothing on the consumer market currently comes anywhere close to that. So for the time being, we'll just have to live with being able to see huge blocky pixels in VR headsets. Since we're going to be seeing the pixels regardless, it's completely up to personal preference whether you like smaller pixels or a wider FOV.

Incidentally, this is why the GPU market still has a lot of growth left in it. CPU performance has pretty much topped out and users don't really need faster CPUs, so Intel has pretty much hit a dead end in terms of growth. The last 5 years or so, they've been mostly concentrating on reducing power requirements instead of increasing performance. But GPUs still have to become more than 100x faster than they are today before they can power real-time 3D VR systems with enough pixels to fool the eye. I suspect eye-tracking systems - which detect where you're looking and only render that spot in high resolution, and render everything else in low resolution - will become real-time capable before GPUs can power a 12,000 x 6000 resolution VR screen in real-time.