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[REQ] Help needed with Nexus 7 VR kit

Posted: Sun Jun 23, 2013 4:55 pm
by disibaro
Hi guys, I'm kinda new to this VR stuff but i did manage to setup a nexus 7 with Freepie, Tridef and Splashtop 2 working with two 3x 50mm lenses, but im having some trouble building the box, I can't seem to find the right measurements for the lenses to work well.

I've tried making a prototype out of cardboard but I can't find the right distance between the screen and the lenses, and the lenses with the eyes. If someone could lend me a hand I would be gratefull and post some pics of the result, cheers ;)

Re: [REQ] Help needed with Nexus 7 VR kit

Posted: Tue Jul 30, 2013 11:30 am
by kwx
As a starting point, the distance from the lenses to the screen should equal the focal length. A "3x" lens should have a focal length of 250mm/3 = 83mm which is rather distant. I used "5x" (50mm focal length) with a Nexus 7 for fairly good results.

If the lens is at 1 focal length distance from the screen, you can view it from any distance with the eye focused at infinity (*). For maximum immersion, you'll want the eye as close to the lens as possible, so that you get the largest possible field of view. If the screen doesn't fill your view, you need a stronger lens. Conversely, if you only see a small part of the screen, it's too strong.

One more thing - start out trying just one eye at a time. Many of the Android VR apps such as the Durovis Dive ones seem to assume a phone-sized screen, and you won't be able to get a stereo view if the image centers are further apart than your pupil distance. I made a demo with user-adjustable settings (if you have a bluetooth keyboard or gamepad), with the defaults adjusted for my N7 @50mm setup: https://code.google.com/p/hackerskeyboa ... oid-HMD-VR

(*) If you're nearsighted and can't focus at infinity, you'll need to adjust the distance.

Re: [REQ] Help needed with Nexus 7 VR kit

Posted: Thu May 08, 2014 6:59 pm
by primus86
try twomon usb