Wow, my brain is gonna explode (small problem). Thanks, Friar! Why doesn't the tv have just the image -- 1 image of the tv on the wall?

It's called video feedback and is analagous to the way you get audio feedback when you allow a microphone to to get too close to a PA speaker.

With a bit of patience and practice some lovely developing/pulsing patterns can be created. For example, the orignal title sequence for Doctor Who used video feedback to create the streaming stripes/clouds out of which the Doctor's face emerges.

Mark

But it does have that! And look at the TV and tell me what you see displayed there. You see the image that the camera is capturing, of the TV. So, on the TV you see the image of the TV. Now, what's on the TV? The image of the TV on the TV, so on the TV you see the image of the TV on the TV. Now, what's on the image on the TV on the TV? The image of the TV on the TV ... on the TV. Now, that's on the image of the TV ... on the TV? The image of the TV on the TV ... on the TV ... on the TV ... etc.

Try zooming in so that all you see is just the TV screen on the TV. All the sub-images zoom in bigger until they eventually overlap the edges of the frame and ... disappear. Or zoom out and they all shrink.

Here's some fun ... rotate the camera slowly and slightly. You'll end up with an infinitely twisting tunnel. Move it around slowly side to side. Melt your brain.

Ahhhhhhhh so! I get it! I actually get it! I'll play with it a bit more with the zoom game.
Thank you so much. Now I can throw this back at my science teacher friend and pretend that I figured it out myself.

tidum

Thank you, Mark. Does this fit with the other explanations posted in this thread? This is the term for it, "video feedback?"

"This is the term for it, "video feedback?" "

Yes, decades ago many music videos were made using pretty much nothing but that effect. It's a bit different to audio feedback, more like reverb, as the delay in the loop is quite long.
Now here's a real brain buster, how to recreate this effect digitally.

Bob.

Ultimate S ?

You don't need electronic technology to see this effect. Just set two mirrors facing each other and stand between them.

Seems like some analog FX boxes used to do this easily.

You could call it feedback but it's really a delay (feedback tends to amplify the signal, which this might be doing if the tunnel seems to just go to white at the center, but that's a side effect)

There used to be a tape-based echo machine called an EchoPlex. It had a tape loop in it, a record head, and a playback head. The playback head was on a slider and there was a handle to move it side to side. The box would record the audio at the record head and then play it out at the playback head. You could mix and patch the output as you liked and feed it back to the record head if that was what you wanted, getting a nearly endless echo that'd degrade into tape hiss. If you fed it back louder than the original the thing would get louder and louder very quickly. You could change the delay time by sliding the playback head nearer or farther form the the record head.

You could probably script this in AfterEffects.

Rob Mack

"Now here's a real brain buster, how to recreate this effect digitally.'

Fractal loop?

"Now here's a real brain buster, how to recreate this effect digitally.'

Fractal loop?

Using After Effects should do it

"Using After Effects should do it "

Thanks (I think), been looking for a reason to learn Expressions in AE.

Bob.

play any video game that uses BSP trees (wolfenstien 3d to anything out now) & look in to "the void." It's called the "hall of mirrors" effect. Some people have used it for very clever game FX over the years.

I used to (hah "used to"! . .still . . ) love playing the 2 mirror thingie. Watching the "curve" and snakily quality and going off into the dimly lit eternity that is . . . . sorry, I wander off there . . . I was always hoping for some "door" to open up into another realm . . . .

Oh yes Dr Who. When I saw this, with my Dad's ancient Panasonic ( still working) I've been hooked ever since . . .

Grazie

I went to an Op-art and kinetic art show many years ago and saw a simple piece that was mind blowing. No electronics required.

It was very simple but may be hard to describe. Three large rectangular mirrors were joined to form a triangular prism. One mirror was lying flat on the ground with the mirror surface facing up. Two other mirrors were attached to opposite edges of this mirror and leaned toward each other to form an equilateral triangle. Sort of an A-frame shape. The two triangular ends of this structure were open and all the mirror surfaces were inside of this prism shape pointing at the other two.

From a few feet away you go, what the heck is that boring thing? But if you stick your head into the space inside the mirrors, there is a fascinating effect. It looks like a million copies of yourself are sticking your head out of as many triangular windows on the side of an infinite skyscraper wall. The thing was big enough so that more than one person could be looking at once so there were clumps of heads in each of the triangular windows. Looking around, the effect goes on infinitely down, left, right and up. Just on the other side of the prism there was another infinite wall of triangular windows parallel to the one filled with your head. If someone looked in the other side, their head would fill the windows on the other wall.

I hope that description was clear enough to visualize the thing.