Pepper’s IGhost

A few days ago on Facebook I saw a post about build of a visual trick that makes a smartphone look like it has a hologram floating above it (props to Ann Cudworth for sharing it). It is of course not really a hologram but a version of Pepper’s Ghost using a trick of light passing through an angled piece of transparent material. This allows the eye to see an object floating or looking transparent and ethereal.
The video shows how this all work and how to build one.

I did have a go with an old CD case but I found the plastic shattered way too much so instead I used a slight more cut-able acetate sheet. I made a quick prototype that was a little bit wonky, but it worked still.
"Holographic" acetate
There are lots of these types of video out on youtube
There are some commercially available version of the such as the Dreamoc which works in a similar way but the pyramid is the other way up.

There are lots of other examples where a visual trick fools our brains into thinking something is truly 3D and floating in space. It’s all done with mirrors 🙂
Some of you may remember the time traveller game

This used a projection onto a bowl shaped mirror. This effect is also used in the visual trick you sometimes see in gadget and joke shops. Such as this one from optigone

There are some fascinating tricks and of course Microsoft Hololens, and Magic Leap will be using “near eye light fields”, which are slightly more complex arrangements than a bit of acetate on an iPhone, but we can appreciate some of the magical impact may have by looking at these simpler optical illusions.
Our ability to do more more light, and not just deal with the flat 2d plane of a TV screen or of a single photo is definitely advancing. The recent camera’s such as the Lytro which is a light-field camera treat multiple layers of light as important. Just as the Near Eye light fields bounce the light through multiple screens of colour and different angles to create their effect.
Whilst sometimes the use of the Hologram word is over used I think that what matters is how it makes us feel as a human when we look at something. The mental leap, or the trick of our brain that causes us to think something is really there is fascinating. If we think it is, well… it is.
At the moment we are still focussed (no pun intended) on altering the images that travel into our eyes and the way the eye works with its lenses and optic nerve to the brain. It is only a matter of time before we go deeper. Straight to the brain. Already there are significant advances being made in helping those with no eyesight or restricted eyesight to have a digital view of the world directed and detected in different ways. So it may be that our true blended and augmented reality is to further augment ourselves. Quite a few ethical issues and trust issues to consider there.
Anyway, back to amazing the predlets with Pepper’s IGhost, time to build a bigger one for the ipad!
**Update Just after posting I made a larger one for the ipad. The predlets enjoyed watching the videos in a darkened corner.
Predlets enjoying holographic effect on ipad
Then maybe an interactive unity3d live version.

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