# Why so many mirror image pictures on the web? **URL:** \ **Category:** Factual Questions\ **Created:** [January 2, 2012, 12:56pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135 "2012-01-02T12:56:47Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [January 2, 2012, 12:56pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/1 "2012-01-02T12:56:47Z")
I’m seeing a trend on blogs and social media sites for people to post their images flipped like in a mirror. Is my sampling horribly skewed or is this an actual trend? And what’s the reason? And no, I’m not talking about shooting yourself in the mirror. These are webcam-images and similar and for some bloggers appear to be universally mirrored. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 2, 2012, 1:09pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/2 "2012-01-02T13:09:26Z")
My sister’s mac, when using the webcam, shoots a mirror image. I assume that’s the reason for all the backwards pictures. Why it does that, I’m not sure. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [January 2, 2012, 1:38pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/3 "2012-01-02T13:38:32Z")
How can you tell? Is there backwards printing in the picture? ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [January 2, 2012, 1:55pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/4 "2012-01-02T13:55:38Z")
I do know people reverse videos on YouTube to try to avoid the automatic copyright tools, but it doesn’t sound like what you are talking about is related. I do admit that I prefer my webcam picture of myself to be reversed. It doesn’t matter which way it is on the other end, but, on my end, it’s horribly disconcerting. If I can’t reverse it, I shut off the ability to see myself and just hope I stay in frame. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [January 2, 2012, 2:01pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/5 "2012-01-02T14:01:44Z")
> [@Fear\_Itself](#): > > How can you tell? Is there backwards printing in the picture? Those are the most obvious, yes. There are also other things that are left-right asymmetric, like clothing logos, or microwave ovens. One can’t tell for all pictures, but you might be surprised of often it’s possible to figure out if a picture is mirrored or not. The Mac explanation seems reasonable, although it’s weird Apple has mirroring as standard. ---
**Author:** ![freckafree](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/freckafree/32/3050_2.png) [@freckafree](https://boards.straightdope.com/u/freckafree)\ **Post date:** [January 2, 2012, 2:10pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/6 "2012-01-02T14:10:45Z")
> [@naita](#): > > The Mac explanation seems reasonable, although it’s weird Apple has mirroring as standard. I assume the intent of the mirroring is so you see an image that looks “right” to you – i.e., what you see when you look in the mirror. In the Photo Booth application on Macs, there is a setting that automatically flips photos, but I imagine most people either don’t bother or don’t flip the photos intentionally, because they look weird to them flipped. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 2, 2012, 2:23pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/7 "2012-01-02T14:23:26Z")
> [@freckafree](#): > > I assume the intent of the mirroring is so you see an image that looks “right” to you – i.e., what you see when you look in the mirror. In the Photo Booth application on Macs, there is a setting that automatically flips photos, but I imagine most people either don’t bother or don’t flip the photos intentionally, because they look weird to them flipped. That’s what I figured for my sister. When she uses photobooth and the like it’s easier to work with if it’s like looking in a mirror. I’ve always found it odd that it doesn’t flip everything back after it takes the picture. I first noticed this a while ago when she shot a video of my daughter and I noticed that the room was backwards…after that when I noticed that writing on clothing was reversed I figured it was for the same reason. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [January 2, 2012, 3:20pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/8 "2012-01-02T15:20:17Z")
[sort of big nitpick] “Flip” is rotation around x-y axis “Flop”–mirroring–is what is being discussed here [/sort of big nitpick] ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [January 2, 2012, 3:44pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/9 "2012-01-02T15:44:14Z")
> [@Leo\_Bloom](#): > > [sort of big nitpick] > “Flip” is rotation around x-y axis > “Flop”–mirroring–is what is being discussed here > [/sort of big nitpick] 😕 You can either rotate an image, or flip (mirror) an image about its horizontal or vertical axis. I can see someone using flip or flop interchangeably without any confusion. Shoot, I even fail to see any difference between your two definitions. ---
**Author:** ![Bear\_Nenno](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bear_nenno/32/3358_2.png) [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)\ **Post date:** [January 2, 2012, 3:54pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/10 "2012-01-02T15:54:25Z")
> [@Leo\_Bloom](#): > > [sort of big nitpick] > “Flip” is rotation around x-y axis > “Flop”–mirroring–is what is being discussed here > [/sort of big nitpick] No Cite? ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 2, 2012, 3:58pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/11 "2012-01-02T15:58:33Z")
> [@cmyk](#): > > 😕 You can either rotate an image, or flip (mirror) an image about its horizontal or vertical axis. I can see someone using flip or flop interchangeably without any confusion. Shoot, I even fail to see any difference between your two definitions. I think what he’s saying is that a flip is upside down and a flop is backwards. A [flipped image](http://en.wikipedia.org/wiki/Flipped_image) or reversed image, the more formal term, is a static or moving image that is generated by a mirror-reversal of an original across a horizontal axis A [flopped image](http://en.wikipedia.org/wiki/Flopped_image) is a static or moving image that is generated by a mirror-reversal of an original across a vertical axis ---
**Author:** ![Batfish](https://avatars.discourse-cdn.com/v4/letter/b/a3d4f5/32.png) [@Batfish](https://boards.straightdope.com/u/Batfish)\ **Post date:** [January 2, 2012, 4:09pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/12 "2012-01-02T16:09:31Z")
> [@Leo\_Bloom](#): > > [sort of big nitpick] > “Flip” is rotation around x-y axis > “Flop”–mirroring–is what is being discussed here > [/sort of big nitpick] Jargon of a particular industry. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 2, 2012, 4:14pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/13 "2012-01-02T16:14:57Z")
What the heck is an ‘x-y axis’? ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [January 2, 2012, 4:56pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/14 "2012-01-02T16:56:29Z")
Ok, we’re going into semantics (in its real sense). Yes, a mirroring is a “flip”-- as described by a human with stuff in his hand–into a position where the image is reversed in depth (flipped into depth, ie into the z-plane). But this mental concept, like rotation, holds on to the physical experience of working with physical material, which makes sense considering how recently the changeover to digital has been. In the non-digital image practice if you take a negative and physically turn it over, usually by accident, the image is flopped. This can be dismissed as “industry jargon,” but normally it takes a while for meanings to change, and initial meanings left to vanish but live on in etymology. That time is, I believe, not arrived full-fledged. But I leave it to common practice, and will regret the loss of specificity of meaning in describing imagery. ::sigh::😉 Note that OP needed to add the words “like a mirror” to “flipped,” whereas the correct word would obviate the meaning. Hijack, but I think interesting in this context: Why, in a real mirror, if light paths are consistent in all directions, do we see ourselves reversed but always standing up? Feynman addressed this. ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [January 2, 2012, 5:14pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/15 "2012-01-02T17:14:17Z")
> [@Mangetout](#): > > What the heck is an ‘x-y axis’? > **[Cartesian coordinate system](https://en.wikipedia.org/wiki/Cartesian_coordinate_system)** > > In geometry, a Cartesian coordinate system (.mw-parser-output .IPA-label-small{font-size:85%}.mw-parser-output .references .IPA-label-small,.mw-parser-output .infobox .IPA-label-small,.mw-parser-output .navbox .IPA-label-small{font-size:100%}UK: /kɑːrˈtiːzjən/, US: /kɑːrˈtiːʒən/) in a plane is a coordinate system that specifies each point uniquely by a pair of real numbers called coordinates, which are the signed distances to the point from two fixed perpendicular oriented lines, called coordin... > **[What is the Cartesian plane, and how do I use it?](https://www.purplemath.com/modules/plane.htm)** > > The Cartesian plane puts two number lines perpendicular to each other. The scales on the lines allow you to label points just like maps label squares. > **[X-Axis and Y-Axis: An Easy Trick to Remember them Forever](http://www.gradeamathhelp.com/x-axis-and-y-axis.html)** > > The x-axis and y-axis can be easily confused, that is, unless you know the GradeA trick. I like the last link … " **x to the left** and **y to the sky"** ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 2, 2012, 5:24pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/16 "2012-01-02T17:24:40Z")
> [@Mangetout](#): > > What the heck is an ‘x-y axis’? I wondered about that too, but if you figure he meant to say z-axis it makes sense. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [January 2, 2012, 5:46pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/17 "2012-01-02T17:46:09Z")
> [@Joey\_P](#): > > I wondered about that too, but if you figure he meant to say z-axis it makes sense. That’s what I thought too, but when you think about it, a rotation about the Z axis doesn’t work. In this context Z axis would usually be considered as “coming out of the page”, and rotating by this axis would be akin to a barrel roll. If you roll a photograph by half a rotation, what was in the top-left corner is now in the bottom right. This is not the same thing as flipping an image where, by comparison, what was in the top left would now be in the bottom _left_. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 2, 2012, 6:02pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/18 "2012-01-02T18:02:40Z")
> [@Mijin](#): > > That’s what I thought too, but when you think about it, a rotation about the Z axis doesn’t work. Put a thumbtack in the center of a picture and spin it [the picture]. The thumbtack is the z-axis. The picture never breaks the xy plane. Rotating something on the xy plane about the x or y axis involves the third dimension (other then a few exceptions). ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [January 2, 2012, 6:44pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/19 "2012-01-02T18:44:12Z")
> [@Joey\_P](#): > > Put a thumbtack in the center of a picture and spin it [the picture]. The thumbtack is the z-axis. The picture never breaks the xy plane. Rotating something on the xy plane about the x or y axis involves the third dimension (other then a few exceptions). Yes, but I don’t think you’ve understand my point. Put a thumbtack in the center of a picture and spin it. Whatever rotation you perform will _not_ be equivalent to flipping the picture. So my best bet for what **Leo Bloom** meant by “x-y axis” is, simply, “x axis”. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [January 2, 2012, 6:57pm UTC](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135/20 "2012-01-02T18:57:58Z")
I work in CG/3D, so x,y,z axis becomes very ingrained. The typical orientation is the x axis runs horizontal, y runs up and down, and z would be your depth – to and fro. If you want to mirror an image horizontally, you would rotate it on its y axis. If you want to mirror an image upside-down, you would rotate it on its x axis. If you wanted to turn or rotate an image (mirrored or not) you’d rotate it on its z axis. Whether or not esoteric lingo exists about ‘flipping = mirroring’ and ‘flopping = upside down’, it’s certainly not standard. If I were to tell a designer to flop that image, and it wasn’t returned mirrored upside down, but mirrored horizontally, I could only blame myself for not being clear. [Next page](https://boards.straightdope.com/t/why-so-many-mirror-image-pictures-on-the-web/608135.md?page=2)