Making a VR (Google Cardboard) Headset with almost any kind of magnifying glass
Time to get VR home… DIY(Read Disclaimer)
Please do keep in mind that this is not the best way to make the cardboard, but just a way for making it without appropriate lenses, which are harder to find, especially in remote areas. If you can get the appropriate lenses for it, please do not continue. If you can get the lens, then try making the actual cardboard 2.0, good tutorials for which are available throughout the net. This is based on the early beta of Cardboard, and is thus, not the recommended way.
The most economical way to experience VR is to use a Google cardboard set. Although it can’t be compared with a real high end headset like the HTC Vive or the Oculus rift, it is pretty good and wonderful, not to mention cool, for someone who hasn’t ever experienced VR.
One of the key problems faced while making a cardboard headset is finding appropriate lens for it, especially, of the specs mentioned in the Google cardboard’s website. I spent more than a week searching for the lens in all the opticians and lab material shops, but to no success.
So, what to do
I found out, based on simple observations, that any magnifying lens(or glass) could be used as eye lens for the Cardboard Headset, subject to its focal length.
The focal length of a lens is that distance from the lens, at which it forms the sharpest image of the sun(roughly the distance it is placed from the leaves for lighting it up).
The cardboard headset works by using a phone screen and using 2 eye lens to make it feel like the screen is placed at a huge distance away. You can make any kind of headset, just ensure that you get 2 magnifying glasses of the same size and focal length. The basic principal is that, the phone displays 2 images, one for each eye, the lens magnify it, and make it look like it’s very large and far away(optics), and thus make it look real. The distance between the screen and the lens should be just a little less than the focal length.
Keep in mind, the lesser the focal length, the lesser the tunnelled vision. Aim for as less focal length as possible and a wider field of view of the lens would also improve the performance. One chief problem with headset made by this method is tunnelled vision.
Based on this knowledge, you can make any design of the Cardboard, and adjust it to suit your phone, and comfort needs. Remember, one lens views only one half of the screen. Also, the shorter the focal length, the better the experience.
How to make it
- Get 2 magnifying lens(or glasses) of same diameter and focal length.
- Take 2 tubes of a length just smaller than the focal length, which when combined side to side, cover the entire phone screen (For example, toothpaste tubes, for small screens). Both the tubes should have the same dimensions.
- cover the insides of the tube with foils, or any other reflective material. This is to prevent tunnel vision by preventing you from seeing darkness around the screen, and thus very slightly improve immersion(tunnel vision is that view, which you get when you look through a narrow tube or tunnel, and it limits the field of view).
- Join the tubes side by side(best method is to tape it). Add a little cotton between the tubes on the side where the lens would be(this would act like padding for the nose).
- Place the eye lens towards the side where the nose padding is placed, one on each tube.
- Now, the basic headset is ready. Launch any VR app and place the phone in such a way, that the join of the tubes is in the center of the screen(where the white on screen divider is). Look through the lens, holding your phone. Check if it works. To tweak with the settings and improve your view, check “ So, what if it doesn’t work?” below.
- Now, we have to make a holder for the phone.
- Take a sturdy cardboard, whose width is about the same, or little more than the width of the tubes combined, and the length is 8–10 cm more than the width of the phone.
- Stick the cardboard to the bottom of the tubes, on the side where the phone is placed. Fold it around the phone and again fold it to attach the other side of the cardboard on the top. Now, you can hold this part of the cardboard after placing the phone in. If you can get Velcro, then attach the Velcro to the tube and the cardboard, to make it stick. Now, you don’t even have to hold it.
- One more (important)thing you can do to make it more immersive is to take a newspaper, whose width is 5–8 cm more than the total length of the Headset and wrap it around the Headset about 5–6 times. Then cut out a curve in the side where the lens are, to make it more comfortable for your forehead to go in, and prevent outside light from entering your eyes. You can also tape the edges, to make it more durable.
- Make a small hole, in the place where your headphone jack is, for Audio output.
Note:- For triggering a touch(for playing games), you can use a magnet. Hold a magnet in your hand, and slightly tap it on the cardboard, near the phone, to trigger a touch. Now you can play some cool games, too.
The basic thing you need to do is to make a box with 2 eye holes, place the lens and place the phone on the other side. The distance should be, as mentioned, just a little less than the focal length. You must place a separator at the center, so that each eye sees only one half of the screen.
Congratulations, your first ever VR headset is ready…
So, what if it doesn’t work(OR how to improve it)?
If you really are the Power type, you will want to make a custom viewer profile for your very own VR Headset, setting it’s parameters. Here’s the method:-
- Visit this website.
- Scroll down, and you will find a QR code, with a URL. Open the link or scan the QR on your phone, which must have some particular sensors(Most phones do!!).
- Place your phone in the viewer and adjust the parameters on your computer, as explained, till you get an optimum view.
- Set the primary button type to magnet(unless you want to build the velvet touch button yourself) Or, if your viewer is open, you can also select touch.
- screen to lens distance, obviously, is the distance from the screen to the lens.
- Inter lens distance is the distance between the centers of both the lenses.
- This should be bottom by default, unless the viewer is oriented in some other direction(see the help section on the website).
- Tray to lens center distance-
9. Distortion coefficients — look at the help section of the website. Slightly tweak these settings till all the lines intersect at right angles.
10. Apply the changes, and you will get a QR code.
11. Now, launch the Google Cardboard App, go to settings, and tap on change VR. Scan the QR code, and… You are all set.
Now, you have a perfectly tweaked Google Cardboard Headset, and you have the knowledge now, to customize it to your heart’s content.
The focal length of the lens required by the Google Cardboard’s website is 35 mm.
The result I got with the DIY VR headset was fine, with the headphones giving a boost to the effect. Another suggestion could be to use head straps, though I didn’t use it.
Some of the apps I would suggest with the headset
- VR Cosmic Roller Coaster
- Cedar Point VR
- VR Swing — virtual attraction
- VR Blockbuster attraction
- Trinus VR(Even though I didn’t try it, it looks really promising)
- Froggy VR
- Roller Coaster VR attraction
- VRSE(Works best with phones with good HD display).
- Youtube — Yes, it has inbuilt support for VR Cardboard, and is pretty good, but again, it requires a good display. Apart from that, it also has millions of SBS(side by side) videos, which should work perfectly with Cardboard with a normal screen.
There are many other apps, which I haven’t yet tried. There are web apps also, which you can get by quick googling. Comment it…
The overall DIY experience was wonderful. I look forward to the newly announced Daydream platform. Do let us know about your DIY experience with the Cardboard…