prisms for phone cameras

why are prisms not used for phone cameras (or are they) ?
it seems to me that prisms may be implemented for bi-directional cameras, for lengthening the focus distance, for widening the view field and stereoscopic  images.

iceng5 years ago
Prisms separate colors due to each color is bent differently upon
entry and exit from the prism medium.

You may want to color correct increasing distance even further.

I don't see the benefit of a 45°or 60° or 90° direction image targeting.

Stereo images need two simultaneous offset images like our eyes.

andreiperi (author)  iceng5 years ago
the idea to redirect light at a 90 degree angle from two light sources to the same focusing lens and sensor. Using high quality mirrors is even better considering the points you correctly rose.
the camera electronics could sample the two light sources (on the same and/ or opposite side ) at a ratio appropriate for the application (stereo or front/back ) viewing.
would there an advantage be derived from increasing the distance of the focusing lenses and sensors from the mirrors ?
If yes, the mirrors will allow that by redirecting the light from the gadget surface (they tend to be ever thinner ) to the camera residing anywhere inside the gadget.
There you go :-)