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Comment by voidz | Hacker News Reader

Fun fact: we are used to seeing our own faces in the mirror image of how others see us. Thus, if you have a picture of yourself which you really dislike, mirror it and see if it helps - on photos we see our faces mirrored from what we're used to, hence why they look off so often, and why it can feel so difficult to get the right picture from ourselves taken.

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Also a fun fact; you can make a non-reversing mirror by putting two mirrors perpendicular to each other at 90°. When you look head on into both mirrors where they meet, you will see your image the same as others see it.

That is cool. Are there other ways to make a non-reversing mirror?

I was thinking of car mirrors.

I have a mirror trick of my own.

You know how there is one way mirrors, when used between two rooms they rely on one room being lighter/darker in order to work.

Well if you purchase a special mirror it is possible to make an optical illusion with three rooms in a row involved.

Each of the rooms furthest from each other can see into the interior room, but not into each other. This makes the sense of space much larger. I must talk to a magician or illusionist to see what other ways exist to achieve similar effects.

A few years ago, a Dr. R. Andrew Hicks of Drexel University designed a non-reversing mirror that is a single sheet of glass. The reflection is slightly distorted, however.

News coverage: http://techfragments.com/inventions-non-reverse-mirror/ https://www.newscientist.com/gallery/dn16585-amazing-mirrors

Photo from his website: http://www.math.drexel.edu/~ahicks/images/opticks.jpg

Very clever!

Aside from illusions there are many interesting proposals using mirrors.

I think most people don't think you can use mirrors with fibre optics to bounce daylight directly into people's houses for indoor lighting. There is also this cool trick you can do by using something called a 'cold mirror', where the visible spectrum is tapped into for lighting but at the same time the IR portion of the spectrum passes through the cold mirror and onto a solar thermal tank for making hot water.

All this, with mirrors!

> That is cool. Are there other ways to make a non-reversing mirror?

I don't know if that counts, but:

Get in front of your webcam and watch yourself on the screen. If your laptop screen is too small, note that modern large screens (usually sold as "TV") are larger than typical mirrors.

If all you need is a quick hand mirror, just use your smartphone in selfie mode.

Note that some phones do mirror the front-facing camera view (though actual photos taken are not mirrored) [0]. Both my Nexus phones have done this, so I assume it's a common Android feature. I don't know about iPhones.

Regarding webcams: Hangouts also mirrors your camera to you during video calls. [1]

[0]: https://www.quora.com/Why-are-selfie-pictures-mirror-images-...

[1]: https://productforums.google.com/forum/m/#!topic/hangouts/Ia...

Doesn't work for my particular application but I'm sure others will find it useful, assuming they don't run into the technological conspiracy to hide reality enigmango discovered ;-)

> Each of the rooms furthest from each other can see into the interior room, but not into each other.

I'd imagine this works with polarising glass rather than actual mirrors. Regular unpolarised light will go (partially) through polarising glass, but once the light has been polarised it won't pass through a second polarising filter that's at a 90° angle from it.

You could try that with two camera polarising filters.

That sounds like useful information, thank you.

For several years, I parted my hair the way I liked the look. I'm embarrassed to say how long before I realized and reversed sides.

I didn't realize the connection until now (even though I understand the way mirrors work). Weird how one often doesn't take that one last obvious step of an inference.

I guess now I'll use a smartphone camera instead of a mirror for grooming.

Most front facing cameras reverse the image to make it look like you are looking into a mirror.

Yes. I just tried that now, and unfortunately, my S7 does reverse the image from the front camera :/.

There should be an option to flip the image somewhere though, to be the right way around.

Use a webcam with the always included AMcap application. Or skype, with the mirror option disabled.

I did this too but I also realized "the way I've always parted my hair" is likely also "the way other people are used to seeing me" and thus "the way other people like it" too. So although I like it "to the left" everyone else likes it when I have it "to the right". I am the only one who doesn't care for that, but I also never see it other than flipped!

I actually find it weird even just seeing myself in a mirror. It's a bit like hearing your own voice in a recording.

The recorded voice thing is similar to the mirror thing. That is how everyone else hears you, but you hear yourself via vibration too, which is missing in the recording and so you sound oddly different to yourself.

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