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Close up stereo-photography

Macrostereoscopy is a confusing term for beginners.

  1.  Macrophotography is close-up photography. A macro lens is a close-up lens.

  2. Macrostereoscopy sometimes means a large stereo base, which is usually used on far distant objects. It is better to call this hyperstereoscopy. It has also been called parastereoscopy. 

  3. Macrostereoscopy also means macro photography done stereoscopically. It is better to call this close-up stereo.

  4. Hypostereoscopy  means a short stereo base as used for close up stereoscopic photography. However, it is not always necessary to use a short base (see Bercovitz formula).

  5. Microstereoscopy is extremely close-up and involves considerable magnification. (So  it gets called "micro" when lesser magnification is called "macro", because we are thinking of the object and not the process...)

 

Methods for close up stereoscopy include:

  1. Move the camera sideways then converge. Preferably the camera axes are symmetrical about the mid line between the two camera positions and convergence is kept to the minimum necessary for the desired horizontal field of view.

  2. Move the camera sideways but do not converge. Cut the frames later for correct window effect. This only works when an object is in portrait format but is photographed with a camera in landscape format. (Explanation for this paradox here. Example using the method here

  3. Construct a sliding table for the camera, (with stops to allow various convergences, if you insist on converging).

  4. Set up a pivot under the object, connected by a bar to the camera, which then rapidly rotates its angle of view while still aimed and focused correctly. To reduce key stone effect, have the pivot behind the object and re-mask the stereo pair.

  5. Rotate the object centred on a turn-table and keep the camera still.

  6. Slide the lens sideways (requires a shift lens).

  7. Rotate the camera and re-mask the stereo pair to a smaller format.

  8. *Use a Nimslo lenticular stereo camera. It takes four pictures. The inner two have a small separation, which is useful for macro work. It will not focus close unless a pair of matched supplementary lenses are used (e.g. 1 to 3 diopters). There is no toe-in and so re-masking is needed for correct virtual stereo window (which is a good thing).

  9. *Remove the camera lens and use two small lenses on an extension tube split by a septum. There is a {commercial version} of this, made in Holland and capable of spectacular 3d insect pictures. Although used on SLR cameras with  T adaptor, the system does not use the through the lens view and a different version is needed for different magnifications. I suspect the superb macro stereo books by Mark Blum may use this method, although he does not clearly say so in the prefaces.

  10. *{ Stereo Wirgin:} two small lenses in front of the main camera lens. A commercial version, no longer made, is the Macro Realist.

  11. *Another sophisticated { twin lens attachment } is available for a single camera, including its lens. This works for video and still cameras which may not have interchangeable lenses, but has to be manufactured separately for each system. The macro version has lens separation reduced, from over 90mm for the standard version and is equipped with a convergence device for adjusting the stereo window. The result is an  over and under stereo pair, properly windowed, on one film frame. There is even a tiny version for real time, rigid, [endoscopic] stereoscopy.

  12. *Use a stereo adaptor with 4 mirrors (or prisms) ("Reverse Cazes viewer technique").

  13. *Set up two surface silvered mirrors at a small angle and aim the camera at the junction (not so good for close-ups)*.

  14. *Set up two mirrors (or 45 degree prisms) at 90 degrees and photograph from each side {lovely insects from Japan}

  15. *One camera looks straight ahead through a half silvered mirror (from Edmonds Scientific). The second shoots the half reflection from 90 degrees to the side. By sliding the side camera forwards and back, the virtual stereo window can be moved. This loses one stop of light, which is no great problem when using close up flash. {John Hart has clear photographs and diagrams of this rig.}

  16. Use a scanner and move the object from left to right side of the scanner for the two views: the scanner optics provides the stereo shift.

  17. *Use a stereo microscope and two cameras. 

  18. For an example using just one microscope and filtered light, see the fly and other tiny creatures in 3D by {van Egmond}. Depth of field is a problem in microscopy, solved by an astronomical program: {AstroStack}

  19. Microscopy by tilting the subject is possible. An example using the USB QX3 "toy" microscope is given here. (However, Intel are no longer making this instrument).

  • If you want links to any other method, notify here:
           
    (This is not a link - has to be typed it into an email program - which avoids spammer's spiders)

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    *Methods marked with an asterisk allow moving objects to be photographed in 3D.With a bit of messing about, they permit flash.

    Flash on camera is not perfect when the camera or subject is moved because the shadows are not the same. However, Eric Scanlon uses  method (1) and flash on camera (plus reflectors) for his orchid stereo pictures and they look fine.

    Example: 15 times magnification of a flower using a shifting camera with no toe in so no keystone distortion.

    Example: 12 times magnification of Tarata flower.

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