...using only your fingers!

 How do you know you have detected the 3-DVG effect?

The 3-DVG detection criteria is valid when precision optical quality holes are utilized. If your home made holes are relatively clean this criteria will still apply though with diminished results.

You have detected the 3-DVG effect when you can unequivocally answer "yes" to all three of the following questions:

1. Is it giving you the clearest and sharpest picture you have ever seen bar none? Switch back and forth between the device and your normal view of the observed picture to ascertain this.

2. Can you look all the way into a good scenic picture (like, out to infinity)? If you have trouble here, increase your viewing distance by three feet and try again. Also, try looking at smaller magazine photos.

3. Does the picture appear to be truly three-dimensional (i.e., stereoscopic)? If you examine a scenic picture containing trees, foliage, or flowers you should be able to distinguish the apparent difference in visual depths of small individual elements of the picture such as leaves on a tree or flowers in a garden. 

It should appear unequivocally stereoscopic though not identical to images from normal stereo pairs. Direct comparison can easily be made by "free" viewing a color stereoscopic pair versus the 3-DVG viewing of one of the dual images.

Presuming you were successful, congratulations are in order. Probably less than a thousand  people in the world have experienced the 3-DVG effect. If you are visually orientated it may represent the most unique visual experience you may have had in recent history. If you are technically orientated, you will really have a problem trying to explain it. If you didn’t see it, don’t despair, roughly 30% of the persons who detect the effect did not do so on their first try.