The "Cha-Cha" method:
Named because of the dance where you lean on one foot, then on the other one. It is enough to do the same, shifting the camera sideways, aiming to keep the same frame.
The drawbacks are many: poor matching of the views, subjects to be motionless, poor control of the base distance. This method is only for still subjects and exceptional!
Stereoscopic camera with two lenses:
These cameras are not common, and difficult to get. The views are almost always orthostereoscopic. They have fixed focal lens. With a fixed base the application is restricted and have not the abundance of the adjustable base methods. however, their precise shutter synchronism make them a good choice for shooting motion. They suit well to indoor photographs with flash.
Additional optical device:
There are additional optical devices that split the two views on the same frame and are fitted on mono-lens cameras, usually 35mm film reflex cameras. The specific size of the stereoscopic couples, the loss of definition due to the half frame of each view, the difficulty of getting correct prints, and viewing them made this method not spread
Shift method with a bar:
An ordinary L shape bar is sufficient. The only condition is to maintain it motionless. A tripod is thus necessary. The preparation of this bar is a cheap accessory that all photographers can make.
The camera is shifted from a place to the other one for each shot. Reserved to motionless subjects, it gives very good results. It is the only possible method for near subjects for which a small base is mandatory. With two stoppers, it is possible to action rather fast. Good quality sliding rules gives precise shifting.
Variations, and all kind of supports allow also the photography at large base.
Finally, the only inconvenience of this method is the lack of synchronism.
It is obviously the most preferred method, and the most all-purpose one. Choose two identical P&S cameras. The zoom is unnecessary, unless to be accurately adjustable on the same focal lenght.
Put the cameras on the same platform; Arrange to be able to set different bases (see the sliding bar page); Add some stoppers to be certain that the cameras always sit in the correct position. Both cameras should see exactly the same image, with identical frame.
I have been using Olympus Stylus which were very convenient because there is a rectangular small frame in the center of the viewfinder which is very helpful to set the cameras.
To trigger the shutter, it is possible to release each one with two fingers, but synchronization is very loose. These cameras are linked with an electric connexion, and when pushing one button on one camera, it makes the same action on the second camera in a fraction of second.
Despite this, it remains some thousands of a second which makes the flashes not matching complete synchronization.


Cameras are offset, one before the other, for small bases of near subjects, otherwise, they are in alignment. This shift doen't affect the photographs shot more than one meter away.
  To know how to fix an electric release cord on the cameras, look at the pages on cameras in the Kap part.
cable for connecting cameras
With this equipment, nothing keep from shooting stereoscopic views with the shifting bar method, or with the sliding bar, using a single camera for specific conditions.


Digital cameras mounted on twin slide bars is giving a very versatile and useful system.
Here two Ricoh R8 cameras are connected with the Ricoh remote control. An additional cable is working in parallel connexion to the former one. Synchronisation is within some milliseconds.
It is possible to fire flashes and to get synchronized videos
Set the base for the main subject of the scene in relation with the following plan against which it stands out.
Usually I calculate SR 6 à 10 for the main subject letting the nearest plans getting higher values. Or I calculate for the nearest plan giving it preset SR value.
  Apply the formula, use a programmable pocket calculator, or get help from tables, or download this calculator which contains all variables and let do simulations..
B = SR .2 . sin (A/2) . K . D . ( D+L ) / L
SR is the stereoscopic ratio
A is the diagonal angle of field
B is the base
K is the keenness K= 0.0004
D is the distance from camera to the subject
L is the distance between the subject and next background.
With a zoom the field angle factor M   has to be considered in accordance with the horizontal field angle at wide angle or tele.
M = 2. tan A/2  and    B = M . SR . k . D . ( D+L ) / L
See the page calculate the base for more details. It describes also a manual calculation method.
If there are many plans between 5 to 50 m a base 60 to 100mm will be fine most of the time.
For other situations or other cases or more accuracy it is necessary to evaluate the various distances. This evaluation work may be boring the first times. Count the number of windows, of cars, of poles, to know the width of a road, the space taken by a tree are all informations and knowledge which will help the worth of the stereoscopist
The factor M will be applied only for the large wide angle and long tele lenses. For near standard focal lengths, let M = 1. Because between 50° and 70° diagonal field the variation doesn't exceed 20%.
 The International Stéréoscopic Union put forward the simple rule Dn ~ B x F* (in mm) with Dn the camera to nearest plan, B the base et F* the equivalent focal length (see angle of field page). When the following plans are not too far it's OK, but a far background it gives a ratio SR> 60,which can be compensated with a wide angle or a greater distance.
The stereoscopic ratio is chosen depending on the equipment but it depends also on the scene, the circumstances, the number and arrangement of the successive plans.
Each picture is a personal choice. However nobody expects to see the furthest plans with a strong stereoscopic effect SR. Meanwhile, hyper stereoscopy is more frequent for near subjects.
After setting  a base value, calculate the SR of several significant plans, near and far.
 The following is an example of a standard scene describing the SR on overall fields of the scenery: When field is:
far,           SR is  1 to 3.
not so far, SR is  4 to 6.
near,        SR is   7 to 15.
close,       SR is 16 to 50
So the overall  is well in accordance with the expected 3D sensation..
If the first plans are not too near, the base can be wider to bring the furthest plans to values around SR 10 to 20.
Which limits in hyper stereoscopy?
In each image there are as many values of SR than of the number  of  details and pairs of following plan. For example a tree can have as background a building and clouds in the sky. It is important that values between first plans and last plans are varying progressively and that these values are similar to what our eyes are accustomed.
We realize that for the closest objects the convergence of our eyes and the depth of the object must be considered.
By experience it happens that an image 3D in which a distinct object in the fore ground reach a S value greater than 50 and be fully seeable. However it shall not be over 70.


The absolute limit would be the image of our thumb at the minimum distance of our clear vision facing a background at the infinite. Let's take 25 cm, the calculation gives SR = 600! But there our eyes will converge, the background will be unclear and make vanish. In fact we have as 3D sensation only the depth of our finger and the SR decreases to 47.
Another example is our fist with our arm stretched Here again our eyes converge and the background been at 1 m or 10 m we see it the same way . In this case  also only the depth of our fist is considered and with D=60 and L = 15cm the SR is around 52.
Obviously the maximum SR value 50 shall be followed knowing that when observing 3D manufactured images backgrounds don't vanish as easily.
 SET  the  DISTANCE  of  the  FIRST  PLAN

The relief is maximum is at the nearest plan and the utmost when the background is further. The ideal thing is to have successive plans stacking one after the other and filling the space. A strong effect of relief between very distant plans is often producing a cardboard appearance like the backcloths in the theaters.


Achieve a desired degree of relief at the first plan  is controlling the base and the distance from the camera taken in account the remoteness of the background.

The box "first plan" of the calculator determines the distance Dn calculated with the base B, the depth L and the choosen value SR.

By active zones, it deals with fields giving a stereoscopic effect. In a photograph, several actives and neutral zones are present and take turns depending on field arrangement. Be able to notice and appreciate them needs experience. To determine and to know these distances avoid to shot to no purpose.
It is also possible to increase the stereoscopic effect by spreading the base, even it is not what the eye would have naturally perceived.
The fact that the formulas are set on the distance D from camera to the field, and the space L to the next following field, eases the understanding of the stereoscopic arrangement of the scenery.
In first, calculate the base relevant to the distance D of the main field, and to the space L of the next following field. Then, verify the stereoscopic effect on the various secondary fields, on the most near foreground, and on the further backgrounds.
Take also in account that a completely uniform background "kill" the stereoscopic effect: for example, a field before a smooth and uniform colored wall, a sky as grey as a fog, or deep blue without any cloud will not stand out as it will do in front of a stone wall, or a sky scattered with clouds.
Knowing which stereoscopic ratio is necessary depending on the equipment, and estimate which one is most suitable to the scenery are the key to outstanding shots.
The convergence, or toe-in is the angle between the optic axis of the two lenses. It is sometimes falsely named parallax..
These are the angles of convergence in relation to the distance:
7 m     0,5°               1,8 m     2°
5m      0,7°               1,4 m     2,4°
3,5 m   1°                  1 m       3,5°
Further than 10 m, the axis are set parallel which is zero convergence.
The convergence center is the intersection of the axes. Convergence induces a negative parallax. It brings the plans closer to the spectator.
The convergence reduces the 3D window violation.


The toe-in shall be decided before shooting pictures.
The minimum focusing distance of many cameras is ~1 m or less and the fixed base of most binocular cameras is the eyes distance, or more. Some binocular cameras have a convergence near 2 ° or a parallax. control..
The good practice is to set the convergence center at the background of the scene. For a landscape it is set parallel.
For a subject between 3 and 7 meters convergence is possible. Some set a small convergence running all times.
 In a room the greater dimension been the diagonal, the convergence will be set to this dimension
Convergence is mandatory. for distance less than 3 m.
With twin cameras the zoom shall be controlled with the same field angle/focal length on both cameras.
Set the camera on the step zoom when this function exists, otherwise it shall be controlled visually which is really difficult.


Step zoom function changes the focal length to preset values at each pulse on the zoom button.
Software like StereoPhotoMaker is able to adjust zoom size differences between left and right pictures.

Because the two cameras are shifted, there are some circumstances where deep objects cannot be correctly visualized.

See as example the two photographs aside, it will be impossible to juxtapose the two handrails, nevertheless, only 80mm separate these two views!