Illusion of no reflection?
December 7, 2010 8:01 PM   Subscribe

If two facing rooms, each the mirror of each other, are separated by a thin wall with an opening in it, would looking through the hole be akin to looking into a mirror without a (your) reflection?
posted by unmake to Grab Bag (14 answers total) 1 user marked this as a favorite
It would really depend on window placement (if any) and whether sunlight was coming in, because even if the rooms were a mirror of each other, any sunlight coming in (and casting shadows) would ruin the illusion.
posted by amyms at 8:12 PM on December 7, 2010

Yes, it would. Is there a particular issue that makes you think it would or wouldn't?
posted by ssg at 8:12 PM on December 7, 2010

In what way? do you mean would we be visually "tricked" into thinking we were looking in a mirror? Almost certainly not -- our perception of "mirror" is mostly based on seeing ourselves in it, and seeing it move with us. If you managed to replicate that part, but change the rest of the background we might be tricked, but it's pretty often that something in front of us looks the same as something behind us (the example i'm thinking of right away is when you have 2 adjacent hotel rooms with the door in between... those are often just mirror images of each other but you never feel "mirror" if you look into one from the other).
posted by brainmouse at 8:13 PM on December 7, 2010

It won't be exactly like looking in a mirror. If the rooms have windows, then the light will not be the same in both rooms. Also, anything you interact with in room 1 is not reflected in room 2: the shadows you cast, your appearance in reflective surfaces, the scuff marks you make in the carpet, etc.
posted by cleverevans at 8:14 PM on December 7, 2010

Best answer: FWIW, I believe that's how they shot this scene from the X-Files.
posted by puritycontrol at 8:16 PM on December 7, 2010 [3 favorites]

Response by poster: I meant to add that the rooms would be identically lit and furnished, and if it makes a difference (for shininess, maybe?) the 'hole' would be a plane of glass. Basically, set up so that no matter where one stands in one room, the view looking at the opening is the same as if it were covered with a mirror.

I was, ah, wondering how they accomplished those shots in movies where someone has no reflection, or their reflection is altered somehow. Before CGI, would a setup like this have been used?
posted by unmake at 8:22 PM on December 7, 2010

Best answer: Before CGI, would a setup like this have been used?

Much too expensive. They'd use double filming, and embed using an optical printer.
posted by Chocolate Pickle at 8:25 PM on December 7, 2010

Response by poster: I think puritycontrol's link pretty much demonstrates my head experiment. Thank you!
posted by unmake at 8:25 PM on December 7, 2010

Your idea is used in this prank.
posted by milarepa at 8:31 PM on December 7, 2010 [2 favorites]

Your idea figured in this, too, by the Marx Brothers.

So yeah, sometimes they did it that way.
posted by Chocolate Pickle at 9:49 PM on December 7, 2010

I say no, though there are technicalities. When you look into a mirror, the (reflected) objects in the mirror appear to be twice as far away as they actually are. If you're looking through the hole, you're presumably at the hole, and so cutting that "distance" in half.
posted by Su at 2:32 AM on December 8, 2010

...objects in the mirror appear to be twice as far away as they actually are.

What you're thinking is that your apparent distance from the objects is twice as far away, due to the double-distance of the mirror. Say, you touch a mirror, then take two steps back, so the mirror-you is also two steps away - bang, four steps apparent difference. If you had a Mulder on one side of the 'window' take two steps away, and a Lenny Kosnowski on the other side take two steps away, bang, an actual 4-step difference still. The mirror doesn't unmagnify, it actually creates the illusion of a room on the other side of the glass, which is the illusion the OP wants to exploit.

But, yeah, light source shadows and reflections may be different if the light isn't coming in parallel to the mirror.
posted by AzraelBrown at 5:09 AM on December 8, 2010

If you were somehow able to make it perfect, you could probably do it. But mirrors aren't perfect, and our eyes expect some of that imperfection. We can see the mirror even though we can also see the reflection.

It is easy to do on film, because the nature of the camera and film obfuscates a lot of those imperfections. That's why a painted backdrop (or now, a CGI green screen) can look so good. Our eyes are just focusing on one thing, and our brains are adding the depth. In real life, our brains won't do that as soon as we are aware of what's going on.

I think much of that is based in the nature of our having two eyes. The bigger the mirror, probably the easier the illusion is to recreate. (IE, a friend of mine had a house with mirrors on a wall. They were so well integrated that I actually thought there was a room on the other side.)

Maybe I'm answering the wrong question- you want to create a scenario where you are trying to convince someone they are a vampire? "Look, it's a mirror, and you aren't reflected by it!"
posted by gjc at 7:32 AM on December 8, 2010

Anything that is non-symmetric about its vertical axis (e.g.., words/book titles/newspapers, photographs/paintings etc.) would need to be reversed in the "mirror" room to complete the illusion.
posted by de void at 8:25 AM on December 8, 2010

« Older Help me booze up my punch!   |   How to create six equally spaced boxes in... Newer »
This thread is closed to new comments.