Close up stereo-photography |
Methods for close up stereoscopy include:
-
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. (Keystone distortion.) Any of the various
methods where a single camera is moved only work on static subjects.
They are useless for live insects.
- Use two cameras and converge (keystone distortion). Described by Rob Crockett.
- Two cameras and do not converge: this does not allow true macro photography because the stereo base is too big.
- Move the camera sideways but do not
converge. Cut the frames later for correct window effect. This only
works when an object is in square or portrait format, but is photographed with a
camera in landscape format.
(Explanation for this paradox, along with a bunch of formulae, here.
- Construct a sliding table for the
camera, (with stops to allow various convergences, if you insist on
converging).
- Use the parallelogram rapid shift mechanism but put
shims under it to reduce the stereo shift.
- 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.
- Rotate the object centred on a
turn-table and keep the camera still. This does not work well if you have a
background which is not rotating. The lights should rotate with the object or retinal rivalry will occur with the shadows. Use a plain paper or black
background. (keystone distortion)
- Rotate the camera and re-mask the
stereo pair to a smaller format. (keystone distortion).
- Slide the lens sideways and take another picture (requires a
shift lens). This does not have keystone distortion.
- *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).
- *A 4 in one ID portrait lens (e.g. Nikon) with close up
supplementary lenses - a similar concept to the Nimslo camera.
- *Remove the camera lens and use two small lenses on an extension
tube split by a septum. Rex Julian in Cambridge, New Zealand, has made this system. There is a {commercial
version} by Hugo de Wijs, made in Holland and capable of spectacular 3d
insect pictures. It is used on SLR
cameras with T adaptor. {Technical details here) It works at up to f90, for maximum depth
of field and so the image is too dim for an SLR viewing screen. It is aimed and focussed by putting the subject
between two rods - which in my experience (using a mono system)
insects are not very tolerant of. A reflector is built in to prevent deep shadows when using on-camera
flash, which is essential for insect work. A different version is
purchased for different
magnifications. The superb macro stereo books by Mark Blum
may use this method, I suspect, although in the prefaces he does not clearly say
how he produces the amazing 3D fish and insect pictures.
- *{ Stereo
Wirgin:} two small lenses in front of the main camera lens. A commercial version,
no longer made, is the Macro Realist.
- Single mirror stereo system
- *Stereo Realist Macro attachment {examples}
- *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. I suggested a friend should buy this for
video macro stereo, but the huge price in New Zealand dollars put it
out of our range! There is even a tiny version for real
time, rigid, endoscopic stereoscopy.
- *RBT camera {stereo
adaptor} { Review } { Photo of RBT Macro in action. )
- *Use a stereo adaptor with 4 mirrors (or
prisms) ("Reverse Cazes viewer technique").
- *Set up two surface silvered mirrors at
a small angle and aim the camera at the junction (a bit clumsy for
close-ups in the field, since the camera gets tied up in the foliage). First used in Russia in 1938, as far as I can tell, but based on Theodore Brown's system for standard stereo photography with one camera. There is a commercial version with bells and whistles.
- *{Steve
Body} has developed a much better version of the two mirror set-up
by adding a third mirror. This keeps the camera away from the subject.
The results he gets on insects are very
impressive. The system is suitable for a single digital camera and
works perfectly with a flash. The stereo pair are recorded side by
side on one image frame, as is true for all beam splitters, and should
work for stereo video.
- *Set up two mirrors (or 45 degree
prisms) at 90 degrees and
photograph from each side.
{Lovely
insects from Japan}
- *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.
The half silvered mirror 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.
- Use a scanner and move the object from
left to right side of the scanner for the two views: {scanner
optics provides the stereo shift.} { - Another
version}
- *Use a lens with two stops in it and a beam splitter
behind the lens ("Nil Melior Stereo Macro" camera designed
and constructed by Jac. Ferwerda.) The RBT adaptor uses a similar beam
splitter but keeps the two camera lenses as well.
- *Two variable spacing lenses on a lens board for a
technical camera: "Baby Bertha 2" stereo camera designed and
built by M.P. Whitehouse. I have never seen it, but this seems rather
like the Hugo de Wijs system built for a big camera.
- *Use a stereo microscope and two
cameras.
- For an example using just one
microscope and filtered light, see the fly and other tiny creatures in
3D by {van
Egmond}. He uses a red and a cyan anaglyph filter, butted together, in the below stage condensor. This way he gets an anaglyph stereo in just one step.
- Depth of field is a problem in microscopy, solved by an
astronomical program: {AstroStack}.
{John
Hart} gives extensive advice on how to use stacking programs and
even Photoshop to increase depth of field in macro photography.
- {CombineZ}
is a sophisticated stacking program by Alan Hadley from England. Some
excellent extreme magnification insect photographs are worth surfing
across to see. (Not in stereo, unfortunately)
{James
Tozour} has used Combine Z for macro stereo of minerals.
One
of {Alan Hadley's
set
ups} uses web cams as if they were film holders. He removes the
microscope eye-piece and cuts off the the TV camera lens, so the
microscope objective projects directly onto the web cam CD chip.
Resolution suffers a bit from the small number of pixels in a web cam.
Somebody is going to cut the lens off a 4 megapixel digital camera one
day and the result should be spectacular.
- Stereo microscopy by tilting the subject is commonly
used. An example using the USB QX3 "toy" microscope is
given {here.}
(Intel are no longer making this instrument, although a
similar device is available). Since the lights do not tilt,
reflections can occur in just one of the stereo pairs and produce
retinal rivalry. But that happens when a stereo microscope is used
visually too. Microscopists do not seem to mind, because a little
rivalry is better than not seeing in stereo.
- * No-Mir3d Method of Dr. Imre Zsolnai-Nagy
Hello dear friends!
Please listen me a little bit, I want share my new one camera without mirror stereo method.
Perhaps I'm not the first person who made similar anaglyphs, but on the Internet, in the 3D world it does not exist.
The method is very simple and similar to the QDOS system, but in the same time is TOTALLY different.
The QDOS does not have stereo base, for this produces ONLY pseudoanaglyphs, without depth of field.
The No-Mir3D system HAS the stereo base and produces real 3d anaglyphs.
(The name: No-Mir3D is from me...No-Mirrors 3D...:-)) )
The method is visible on the { attachment } and I think it is very comprehensible!!!
So: we must cover the lens and we must do 2 little holes. The holes must be covered with red and cyan filters.
In this case you will have a ONE SHOT 3D anaglyph on your film or chip and the stereo base is the distance between the holes. For this little base the system is good only for MACRO3D.
This is the No-Mir3D method...
BUT BEFORE STARTING YOU MUST KNOW THESE PARTICULARS TOO!!!!!
1.The system is good only for long focal lengths, for my opinion from 130-150 mm or higher. I tested it with 160 mm, 360 mm, 480 mm and 720 mm.
It is independent: the lens is macro or not.
2. The system works only with NORMAL FOCUS lenses. With RETROFOCUS LENSES; does not work. Usually the compact digital cameras has RETROFOCUS lenses. My Fuji Finepix S7000 fails with the No-Mir3D, it has retrofocus.
3. The DIAPHRAGMA (aperture) MUST be OPENED AT THE MAXIMUM SIZE, without this the system fails.
4. The lenses that I tested worked fine with HOLE - DISTANCE about 10-15 mm. Depends from the lens size (diameter) and from the maximum opened diaphragma's size. The size of the holes (diameter) is good when it is 3-5 mm.
5. Of course WTHOUT FLASH the system does not work. It is good when you have an external good light too.
6. The system produces FULL FRAME anaglyphs.
I think it is all for the moment. You can start to try it, I will be very glad to see some results.
Perhaps a lot of people will have negative opinion and will write the limits of this system. Already now I say: I know well the limits, but show me another similar simple method, for shot macro 3D with only one camera...
At this time please to see the positive side and possibilities of this method.
And if you have a little respect for me, so you will use this name:
No-Mir3D, and I will be very happy!!! Thanks!
I offer and share the No-Mir3D gladly to all my friends and to all people in the 3D world....I hope will be helpful for a lot of people.......!!!
I want say another thing.
The automatic flash, with the max opened diaphragma, works with low light.
So it is good to use the flash in manual mode (if it is possible) or you
must use an old classic flash in manual mode...
Cheers
Imre
- Bens lens is a mirror system for taking anaglyphs in one step and could probably be used in the macro range too - I have not actually heard of this being done. The Guillaume Dargaud method for direct anaglyph photography works on out of focus levels and is an untried technique in the macro range, so far as I know.
*Methods marked with an asterisk allow moving objects to
be photographed in 3D.With a bit of messing about, they permit flash.
Synchronised flash with two separate cameras is a challenge.
Flash on camera is not perfect when the
camera or subject is moved because the shadows are not the same. However, Eric
Scanlen uses method (1) and
flash on camera (plus reflectors) for his orchid stereo pictures and they look
fine.
How to take 3D
photographs
Other links to macro 3D
Electron microscope stereo including snow crystals