Stereo photography

[Xenedis]

Has anyone experimented with stereo photography?

Today I stumbled across the following image:

http://www.flickr.com/photos/ytf/5846267208

It's actually a pair of almost identical images, horizontally offset by a small amount.

The idea is to view the image from two or three feet away, and cross your eyes so that the two images appear as three. If you have the ability to throw your vision like this, within a few moments you'll see one image in 3D.

It's very cool -- to my eyes, at least.

I had heard of stereo photography, but never paid attention to it.

Now I am intrigued. I think I shall read up about it, and I might start experimenting with stereo photography if it's approachable.

[ricktas]

I have a 3D camera, and I can either do digital 3D or stereoscopic, must say I haven't tried the stereoscopic version, maybe I should.

[colinbm]

Hi Xenedis
Yes it is very addictive & simple if you have two identical Canon Point & Shoot cams.
Have a look here at SDM
http://stereo.jpn.org/eng/sdm/index.htm
This is an off-shoot of the CHDK group
http://chdk.wikia.com/wiki/CHDK

I have got two Canon A570IS cameras with identical firmware, & I have made them onto a frame to hold then together & the combined USB trigger etc
Unfortunately I am brain dead, & I haven't got around to getting them to working models
The SDM & CHDK groups are very interesting & is much, much more then it seems.
Cheers
Col

[Scotty72]

I saw a guy at the protest today with this sort of setup: two 5Ds set into a bracket and connected via a cable.

Very cool.

[Xenedis]

I'm curious as to what goes into producing the three-dimensional effect, and thought that maybe it could be achieved by juxtaposing slightly cropped versions of an existing image: one with a small amount cropped off the left side, and the other with the same small amount cropped off the right side.

While I was able to throw my vision, the true 3D effect wasn't apparent in the image.

There's obviously something more to it, and I clearly have some reading to do. :-)

[Scotty72]

Well, our eyes perceive depth by giving us slightly different versions of the same scene. Our brain then triangulates the image and then, depth.

Maybe it's the same principal..

Scotty

[Xenedis]

I gather stereo photography requires two cameras.

That might make it a bit difficult.

[colinbm]

I have heard of some guys doing a moon shoot with one on the east coast of America & one on the west coast & shooting the moon together at the same time, when the moon was half way across the American continent
Col

[Scotty72]

Expensive too

[colinbm]

It can be done with one cam. You will need to take one shot & very carefully move the cam by about 55-60mm sideways, but on the same plane & shoot again.
It is like closing one eye then, closing the other eye & you see two slightly different perspectives of the same view. One left, one right.
Col

[Xenedis]

It can be done with one cam. You will need to take one shot & very carefully move the cam by about 55-60mm sideways, but on the same plane & shoot again.
It is like closing one eye then, closing the other eye & you see two slightly different perspectives of the same view. One left, one right.

It sounds like the sort of technique that would require a dolly.

I wonder how the focal length (ie, ultra-wide vs. long telephoto) would affect the amount of parallel distance required between shots.

[Scotty72]

But, u must be very precise: move it exactly sideways. Not a tiny bit up/down or forwards/backwards.

[mechawombat]

my original pentax optio 3.1mp P&S had this feature and I never used it

I feel the whole 3D thing gimmicky but great find Xenedis

[colinbm]

If you look at the SDM site all will be revealed.
Close-up can be closer then the human eye space 55-60mm.
Further afield landscapes can be spaced wider.
Col

[ricktas]

The FUJI can take either HD 3D or stereoscopic photos if anyone is interested in getting into this. Or the older FUJI can take SD 3D. It is probably an easier way than buying two camera's and joining them together with tape etc.

[Mick B]

Here's one I did about 5 or 6 years ago.
With your eyes approx 12 inches from the screen, stare cross eyed at the black strip between the two photos. You might have to experiment with the distance until you can see a 3 dimensional picture which will appear in between the two

[Scotty72]

Hmmm.

I kinda don't see the point of an image if you've got to stare cross-eyed at it.

[Mick B]

Don't worry Scotty, I can't see the point either. That's why I only ever made 2 of these photos ! It's just interesting to see what can be made from a one dimensional image.

[ameerat42]

Yes. Posted a 2ple in an early thread or 2.

[ytf]

Such an interesting discussion: so interesting, in fact, that I have joined your forum in order to participate and perhaps answer some of your questions.
Thank you Xenedis for bringing my work to the attention of the forum.

As has been pointed out, the stereo photo is two separate photos taken several inches apart.(Yes, I'm American: I live in a world of inches, quarts, miles, etc.) I use a single Nikon D700 with older manual lenses. Since each photo needs to be as similar to it's mate as possible, auto-exposure and auto-focus can actually be a detriment. The benefit of a single camera is that the stereo base (distance between shots) can be easily varied depending on the subject matter. A general rule of thumb is a base 1/30th of the distance from the camera to the nearest foreground object. I don't actually measure, I just wing it. Some of the macro and pin-hole shots are only fractions of an inch apart. Others are as much as 40 or 50 feet. The result is a feeling of seeing the world as a Lilliputian in the former and as a Brobdingnagian in the latter. One also needs to take into account the focal length of the lens being used. I like a wide angle (my most used lens is a 20mm but I sometimes use a 200mm as well) which tends to require a wider base relative to distance than the longer lens. For instance, when shooting a cityscape from across the East River, my base is ideally about 35 feet. With the 200mm, however, I would shorten that to about 8 feet.

There are several cameras available which use 2 lenses and capture 2 images with a single snap. The greatest benefit to these cameras is that they can capture action. Me, I'm more of a still life kind of guy, so I have no real need for such a camera. A third option is a dual-camera rig. The most popular is made from a pair of Canon Point and Shoots using the CHDK hack to synchronize them. On could also use a pair of more advanced cameras, but the complexity rises exponentially when you consider that focal lengths of zoom lenses and focal planes need to match for each frame. The more complicated the rig, the more that can go wrong and fancy dual-camera rigs can get very pricey. I subscribe to the KISS principle (Keep It Simple, Stupid.) Since I shoot in a very crowded, fast moving environment, (New York City) I need to be able to shoot quickly and move on. Fiddling with gadgets is not an option.

There are a variety of viewing methods for stereo photography. The most traditional is parallel, in which the left-eye image is on the left and the right-eye image is on the right. I find this somewhat limiting in that most people (myself included) cannot freeview such an arrangement. A special viewer is needed and there is generally a limit to what sizes can be presented. An alternate and also rather traditional method is the red/cyan (anaglyph) method, long the staple of early "3D" movies. It is reasonably effective, but it tends to screw up the colours quite a bit. The third popular method is crossview. The left-eye image is placed on the right and the right-eye image on the left. The viewer crosses their eyes slightly until a single image with depth forms in the middle. This tends to be the most popular these days. It is rather simple to do, requires no special gadgets, larger sizes can be seen easily and the colours remain true. Note that no matter which viewing method is used, the photo can easily be changed to other styles. Most exhibitions are done using dual projection systems in which the images are mounted parallel.
Crossview is not nearly as difficult as it seems. Most people are quite capable of it and in fact do it constantly in their daily life without even realizing it. Try this: hold one finger up in front of your face. Without diverting your gaze from the finger, take not of things that are farther away. They will be double. Crossview is the same principle. With a bit of practice you can train your eyes to converge at a point closer to your face but focus on a point more distant. It is no more uncomfortable than if you were reading a book. If it feels uncomfortable, you're probably trying too hard.

One comment I read is that it seems like a gimmick. This is said about many things we accept in life. Painters have said that photography itself is a gimmick. Stereophotography is actually nearly as old as photography itself. In fact, Sir Charles Wheatstone presented the first treatise on binocular vision, describing the process of dual imagery, to the Royal Society in 1832. For those who know their photographic history, you will know that this was several years before the first photograph. The most widely accepted date for the first stereo photograph is about 1852. The first camera to use 35mm celluloid film was a stereo camera. In fact, stereophotography was widely used and accepted until the advent of Kodak's simple cameras made for use by the general public in the early decades of the last century. In order to reach the largest market, they kept it simple. (So much for KISS) Rather than partaking in a new gimmick, I consider myself upholding an old tradition. For the record, I'm not into 3D movies. I think I've only seen two in the last 30 years, and neither one was Avatar.

Feel free to browse my Flickr stream, www.flickr.com/photos/ytf. If you have any questions or comments, I would enjoy hearing them.

ytf