A cloaking device that is easy to make.

[TreeTopsRanch]

[youtube]http://www.youtube.com/watch?v=vtKBzwKfP8E[/youtube]

[Steve Grisetti]

People have been looking right through me for years.

[Dave McElderry]

It would be interesting to have more of an explanation of exactly how it works. But then it might be beyond me. It's not new - the Klingons have had cloaking devices for quite some time.

[John 'twosheds' McDonald]

It's not new - the Klingons have had cloaking devices for quite some time.

[TreeTopsRanch]

So, how does it work? The first 200mm lens makes a focal point 200mm from that lens. (You can see that point clearly in the video's thumbnail image above. Put the cloaked object here.) The first 75mm lens, which is 75mm from this point, straightens the rays. Unfortunately, the view is now upside down. That's where the second pair comes in. It inverts the effect and puts things right-side-up again. This works no matter the distance between the two pairs as the rays between the pairs are straight. So why the specific distance between the pairs? Because at this distance, you get the proper 3D effect as the viewer moves off center. At other distances, the background would move too much or too little as the eye moves off center.