How to set the correct stereo separations when using a HMD

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crim3
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Which stereoscopic 3D solution do you primarily use?: S-3D Projector Setup
Location: Valencia (Spain)

How to set the correct stereo separations when using a HMD

Post by crim3 »

Maybe it's obvious to others, but it took me 2 years to realize it, so I will share it.

As you know, the most accurate stereo effect is achieved when the separation match the inter-pupil distance of the viewer. It's easy to set it correctly when using a monitor or projector because you can grab a ruler and measure the separation of the two images (left/right) of the same object that is far enough (at infinite) and increase/decrease the setting until the distance measured over the screen is correct (I still don't know how to do it with iz3d drivers, as the convergence setting affects the separation of objects at infinite).

But you can't do that directly inside a HMD, and it's been a problem for me all this time as I've tried to use guess values which resulted to be wrong... very, very wrong.
Hopefuly, once I found that I was using a wrong value (ironically trying to rise the separation over the limit) I realize that it can be easily done using my desktop monitor and taking into account the proportions between the monitor and the apparent screen in you HMD.

For example, the diagonal of the viewable area of my monitor is 18", whereas the diagonal of the z800's screens according to eMagin is 105". Then, with a typical eye separation of 6 cm, all we have to do is:

stereo separation = 6 cm * 18"/105" = 1.03 cm

(don't worry about the mix of cm and inches, the inches cancel each other and all you get is a proportion)

So, when in my monitor the separation between the images is around 1 cm, the separation in my HMD is around 6 cm.

I've been 2 years using a separation that is about 6 times greater than the correct one for me... pathetic... :roll: That's why I could not be completely happy with the settings, of course!!, now everything makes sense.
Well, at least, I think that I've demostrated that stereo-3D does not hurt sight.

Now the stereo effect is more accurate and easy for the eyes. I specially like the sense of speed in Live for Speed. Having objects of the right size no matter the distance to the objects changes the whole perception of distances, sizes and speed.
Zalman Trimon ZM-M220W / Acer H5360 with Another Eye2000 shutters / nVIDIA GTX760

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cybereality
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Which stereoscopic 3D solution do you primarily use?: S-3D desktop monitor

Re: How to set the correct stereo separations when using a HMD

Post by cybereality »

Yeah, I realized some time ago that you don't need a high separation for good 3d effect. Just a little bit can go a long way.

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