VR headset FOV Calculator
Change the values in the boxes to calculate your VR headset Field Of View
you need about 100-200 cm distance between you and the wall to do this.
- place something to mark a center point on a wall. (blue circle in diagram)
- place 2 markers the same distance, one to the left, and one to the right, at the same height as the center mark, from the center mark. A good distance to use is 100cm. As long as the distance is about this value, and the same for both sides, you will get a good result.
- face the center dot with the viewer in hand so that you can take it off and put it on freely. Put on the viewer so that you can see the edge of the viewer's view. Change your gaze to look at the edge of the view, vs using your peripheral vision to do so. Both give similar results, but let's keep it consistent between users. This could mean that you are seeing past the edge of your phone, or this could mean that you are seeing the inner wall of the viewer. Whatever it takes, make it so that you can see that edge. Now step backwards (make sure you don't bump into anything or trip over anything) away from the center dot. As you step backwards, put the viewer on, take it off, etc, checking to see if at any point the left and right gaze line hits both the left and right dot. Eventually you will have walked too far, so step forward. Eventually you'll be standing at a position where if you close your right eye, and look at the left edge of the left view, and take off your viewer, your left eye will be looking directly at the left dot - and the same for the right eye (close left eye..etc). Remember, don't try to see the marks on the wall through the lenses. The lenses converge your FOV. You want to only compare the position of the edge of your vision looking through the lenses (which is a function of eye to lens distance, effective lens diameter, and inner walls of the viewer if it is poorly designed) , with the position of the marks you see when removing the viewer from your face (but not moving the position of your head or single opened eye)
- Put a marker on the floor, and measure the distance to the center point on the wall along the floor. That will give you the L. The distance between the center mark and the other two points on the wall will be you R.
- FOV = atan(R/L)*2