Would a sapient being sensitive to polarized light be able to see the angle of polarization in a photograph?
Many animals have the ability to see polarized light (or rather, are sensitive to the direction of polarization), most notably birds and bees but also a wide range of other animals including cephalopods, many arthropods, and some vertebrates. Several of these species are thought to navigate by using the polarization patterns to determine the exact location of the sun, and use that as a compass to navigate. Some species are even capable of detecting polarized light in night conditions, thought exactly how is still controversial. Depictions of how these animals see polarized light (as well as mock-up devices intended to mimic this effect for human eyes) show the direction of polarization as banded patterns visible on the sky. Humans can see polarized light but we aren't that sensitive to it and can't use it to navigate like other animals can.
My question is this, given that these polarization patterns appear to be visible on the sky, would a sapient animal (that can therefore communicate what it sees) with the ability to see polarized light be able to identify the general orientation that a photograph or video had been taken from based on polarization patterns in the sky in the background? Or do most cameras not record that kind of information since the information being captured is intended for the human eye, which is more or less insensitive to polarized light?
EDIT: As a clarification, what I mean is would an alien sensitive towards polarized light be able to determine the direction at which a photograph or video was taken based on a photograph taken on a camera built by and for humans (i.e., cameras seen in everyday life), rather than a special camera built by the aliens specifically to take pictures/video accurate to their polarization-sensitive vision
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1 answer
Maybe... but probably not.
It's possible that an animal that is "used" to seeing polarization would be able to infer this information from a reproduction that lacks it, based on other effects. This would probably depend highly on what was photographed. A human could conceivably be trained to recognize the same sorts of cues.
However, as others have noted, human-designed cameras aren't designed to capture polarization information, nor are human-designed reproduction technologies generally concerned with reproducing polarization.
Moreover, accurate reproduction of polarized light such as you are describing would be quite difficult. You might, with sufficiently advanced deposition techniques, be able to lay down pigments in a way that produces the desired polarization, however this a) may be sensitive to the illuminating light source, and b) will probably more closely resemble the sort of lithography process used to produce complex microchips (e.g. CPUs) than inkjet printing (offset printing is right out). As a result, they will either be very expensive, or your hypothetical sophonts will be very good at nanomanufacturing, which will have a significant impact on many areas of their technology.
For emmisive displays, the situation is both better and worse. LCD technology leverages polarization in order to change the brightness of pixels. This means that pixel brightness and polarization direction, at least in a human-designed display, are directly coupled. The good news, however, is that I think you could replace the fixed polarization layer of a typical LCD with a second liquid crystal layer, which (in theory) would allow you to control the direction of polarization independent of the brightness. The same should be applicable to OLED displays, but note that you're going to be giving up a fair bit of brightness.
As to making a device that can capture polarization... I'm not aware of any sensor that can record it directly. The two techniques that come to mind are to have a polarization equivalent of a Bayer filter, which will of course eat in to your effective resolution, or read the sensor multiple times with a different, uniform polarization filter in place. (A bespoke camera might incorporate a liquid crystal layer in front of the sensor for this purpose.)
How do critters that can see polarization do it? Does biology have a solution, or does it "brute force" the problem as in one of my ideas? (AFAIK, biology detects color the same way as modern cameras, by having individual elements with different frequency responses; in effect, the Bayer filter is just copying from biology.)
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