#### Presentteck

##### Member

- Joined
- Oct 3, 2012

- Messages
- 139

- Points
- 18

I found this prism a few years back and was amused with its rotational effects. When rotated around the viewing angle, the image rotates twice as fast as you move it.

I couldn't find any explanation, possibly because I don't know the correct search term to find it.

I took the prism out of its housing to find out why today.

The base side is mirrored, and it's an isosceles triangle. 62.046 base angles and 55.908 at the peak.

I did some math, then I just shined a laser close enough to the side to see, and marked paths. Way easier.

Since theirs a mirror the traced paths shown make total sense on paper. But I can't wrap my head around the rotating 2x movement effect with the 2D representation.

Does anyone know what this is called or how it works?

Here's a link to a bunch of images of the effect.

Also have full sketch of prism, including light paths.

https://m.facebook.com/pg/presentte...id=756494047836021&ref=page_internal&mt_nav=1

________________________________________________________________________________________________________________________

Check out PresentTeck Labs for cool Projects, Art, and Explosions! :gun:

Facebook - www.facebook.com/presentteck

Youtube - www.youtube.com/presentteck op:

I couldn't find any explanation, possibly because I don't know the correct search term to find it.

I took the prism out of its housing to find out why today.

The base side is mirrored, and it's an isosceles triangle. 62.046 base angles and 55.908 at the peak.

I did some math, then I just shined a laser close enough to the side to see, and marked paths. Way easier.

Since theirs a mirror the traced paths shown make total sense on paper. But I can't wrap my head around the rotating 2x movement effect with the 2D representation.

Does anyone know what this is called or how it works?

Here's a link to a bunch of images of the effect.

Also have full sketch of prism, including light paths.

https://m.facebook.com/pg/presentte...id=756494047836021&ref=page_internal&mt_nav=1

________________________________________________________________________________________________________________________

Check out PresentTeck Labs for cool Projects, Art, and Explosions! :gun:

Facebook - www.facebook.com/presentteck

Youtube - www.youtube.com/presentteck op:

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