Just recently, Yahoo.com posted images that have a 3d effect without any glaesses and here is an example of one of them:
How is this done? I searched all over but can't find any good tutorial. I know it has something to do with distorting an image a certain way.
While technically this isn't a "3D" photo, it does simulate a three-dimensional look by exploiting parallax displacement. Cameras are what we call "monocular" devices, in that they have a single lens system and single sensing device. As such, they are not parallax devices, and cannot sense depth directly...only indirectly via other effects such as depth of field. The human eye is "binocular", in that there are two lenses and two sensing devices offset from each other along a single plane. This gives us the ability to detect depth for the very same reason the image in your question has a pseudo-3D appearance.
The sample image simulates a binocular device, or perhaps even used a binocular camera setup, to achieve a modicum of depth perception and provide the photographer with the ability to simulate 3D. You could achieve the same effect with a camera on a tripod, and the use of a macro focusing rail set up parallel to the scene would probably make the job a bit easier. Set up the camera on the tripod, and point it at a scene that has a variety of objects at varying depths. If you shoot a scene with most objects far, and no objects near, you won't really see any kind of "3D" effect if you created a 2-frame GIF like the sample you posted. Set the camera to manual, configure your exposure, and take a photograph. Now, shift the camera to the left or right a small amount...say maybe 5-6 inches (you might need to experiment to find an ideal amount of shift to perfect the effect). Using the exact same exposure settings, take another photograph. These two photographs should essentially be the same, with only a slight shift parallel to the scene.
Near objects will appear more shifted in the second photograph relative to the first than far objects. This is parallax motion, and demonstrates a facet of perspective. You will need to fine tune the images, crop them identically, and scale them down a ways (probably to the size of the sample image you posted). In a tool like photoshop, you can create a two-layer, two-frame GIF image using the animation panel. Show only the first layer for 1/2 a second, then show only the second layer for another 1/2 of a second. Play back the animation, and you should see something similar to the flying alligator and that poor little girl.
I honestly can't say much about the flying alligator...your on your own for that one. ;)
To add to jrista's excellent answer, this technique is commonly known as "Wiggle 3D" or "Wiggle Anaglyph", so google for that to come up with more information and examples.
Adorama has a tutorial on how to make them.
Also, there are several 3D camera apps for iOS and Android that make these.
It's very simple. This is called wiggle stereoscopy or wiggle 3D. See Wikipedia for the explanations.
Jrista made an excellent answer. In short: Take two pictures with a normal 2D camera. Just shift the camera between the pictures. Then load the two images in an image editing software in two separated layers, adjust the position and rotation, crop them and export them.
The first difficulty is to adjust both images as very slight shifting or rotating will spoil the 3D effect.
The second difficulty is to produce a convenient output. Animated GIF produces big files, specially if you are using a transition effect between the both images. But, you can also use two images or one side by side and use Java Script or CSS to display and hide one image on a web page (see example link below).
The third difficulty is the time spent per image. Only a few percentage of the images is suitable for wiggling. And you will see the results only when all the work is done.
There is software around easing this process. I am related to one of the company so I can't put any link here.
But I put some examples of adjusted wiggle 3D images, displayed out of two JPEG images wiggling with CSS, on my private web site http://www.tomic.ch/wiggletest/
