You seem certain that the VR experince isn't well calibrated? Why?no it isn't. As you go passed a planet or star you are well aware of it being a 3d shape. It has stereoscopic depth. In reality we would see something large and distant as flat.
Look at distant clouds, they don't appear as 3d they appear as a flat plane, you only realise their size and distance when you take in to consideration other things in your view like trees , hills and buildings.
You focus on planets as if they are 10ft balls at 5ft away.
The other day I replaced the foam on my Rift. At first I didn't get the thickness right, leading to some strange parallax issues, but that disappeared once I slimmed down the new foam. It's "completely" gone with the thickness of the original foam. It seems to me that the optics (FOV) is pretty well calibrated.
With regards to the images seen through the optics, they seem to be pretty exact scale as well. If not, you would see much more curvature on straight lines, and when you fly towards a giant star, even though it looks the same size as a small one, if you try and measure it (hitting the exclusion zone), you'll find that the size matches.
Motion helps the brain determine size, just like relating the clouds to things close to the horizon. You get a lot more sense of scale when moving towards the star or the clouds, but when you move at several times the speed of light, it's difficult for the brain to relate to anything it knows. Add parallax and it helps the brain even more, which is why the two flat 2D images we see, in the brain, gets transformed into something that we perceive as a big ball of fire.
If you look at the scale of the surface details of the larger stars in ED, even that matches scale, to a certain degree:
But it's still hard for the brain to comprehend the true size of Betelgeuse.