How
to Create 3-D Images without a Stereo Camera
THE
BASICS OF STEREO
PHOTOGRAPHY:
A stereo image requires two different photos of the subject.
Essentially, one photo is taken from the position of the left eye, and
the other from the position of the right eye (the distance varies with
the size of the subject as detailed below). When the two images
are placed side-by-side and viewed through a pair of stereo-viewing
lenses, the images merge and the brain sees them as one 3-dimensional
image. When I was a child I made a viewer using the lenses from a
pair of toy binoculars, but simple, inexpensive viewers made for the
purpose are
available by contacting me--contact Jane
Walker, and from other stereo image sites online.
THE CAMERA:
If you have a stereo camera, you probably don't need to read this
article! I don't--I use a Nikon Coolpix 995 digital camera.
These instructions are for users of non-stereo (mono) cameras.
Digital cameras with viewing monitors work well because you can
immediately see if you got the images right (with a little practice),
and you won't waste money having bad images printed if you have a
computer and software for processing them. However, any
camera can probably be used to take the photos.
TAKING THE PICTURES:
The subject MUST remain still! I took a picture of my dog and she
shifted her nose just a fraction between shots, so in the stereo image
her head pops forward too much and her muzzle looks a little bent!
~
The
camera must
only move sideways between shots, there should be no change of tilt
in any direction, and it must remain at the same height. This is
made much easier if you use a tripod, though rough ground may cause
this to be impractical (when photographing landscapes this is not
always vital, but with still-life and close-up images it
is). My husband and I made a simple slider out of scavanged
scrap metal and some bolts, washers, and nuts so that I don't have to
move the tripod. Sliders can be purchased from some online 3D
vendors, but they are a bit pricy for me.
MY SLIDER:
Click
on
thumbnails for larger images.
~
Leave
extra space on each side of the subject in the images because moving
the camera only sideways will otherwise create a tendency to lose part
of the subject if you crop too close in the view-finder. Also,
cropping the sides is usually required when creating the stereo
cards. Because of this I always take horizontal images even if my
subject is vertical.
~
It is best to use as square a composition as possible if you are making
Holmes-style cards. The finished 3D image will look best if the
composition is square or nearly so.
~
The
distance
you move the camera between shots will affect how 3 dimensional the
finished image is. I usually take several sets of images if I'm
not sure of the best distance. When photographing small or
close-up objects, move the camera only about an inch. For average
subjects (furniture or a shrub, for instance) move the camera about
2.5" to 3". For modest, close landscapes 6" or so will make them
nicely 3D, and for huge distant landscapes several yards between shots
may be required to capture them adequately.
~
Everything
in
the image should be in focus, so use the greatest depth-of-field your
camera can produce, or, if you have sufficient knowledge and control,
use whatever depth-of-field will ensure that everything in the image
will be in focus. There are several way to do this, but you will
have to look elsewhere for instructions--I had to read my camera's
instruction manual to figure out how to do it on my camera, and I have
no clue about any other cameras. Some less expensive cameras have
lovely depth-of-field automatically.
~
I usually take several pairs of photos of my subject, especially if I'm
hand-holding the camera. I take the left photo then the right
photo in sequence for each pair. This way if I flub the camera
position once or twice I will usually still get a pair that will work.
PROCESSING THE PICTURES:
I have a digital camera, a computer, Photoshop 7.0, and an Epson 2200
printer. There are other methods for creating stereocards, and I
will try to find them and post the information or links as soon as I
can.
~
This
is
my
method: I pop images into Photoshop and check them by placing
them side-by-side on the monitor and using a plastic 3D viewer to see
if they work well enough to suit me. To do this part I adjust
each image window
into a 3" square with the image "zoomed" in or out to fit. The
images may not be very clear, but this is a useful first step to see if
the 3D effect is good and the composition satisfactory.
~
I then size the images to match my card blank (see below), and crop
them roughly to fit, leaving extra all around for aligning them in the
frame.
~
I have several different "card" blanks already prepared in Photoshop
with a black background and white "frame" as a separate "Layer".
I just make a copy of the blank I want to use and "slide" the images
behind the frame--see
illustrations:
Some familiarity with Photoshop is needed to make the cards this way.
~
Printer:
My Epson 2200 is a "semi-professional" quality printer designed for
high quality printing. An "every day" quality printer probably
won't be good enough to make satisfactory 3D images. The dots of
ink become visible under the magnification of the viewer and interfere
with viewing the image. However, you can create 4" x 6" "cards"
on your computer and then have them printed as photos at a photo
lab.
~
Printing: I print my cards at 400 dpi, 3 cards per sheet, on 8.5"
x 11" Inkjetart Micro Ceramic Gloss Plus paper. This is the
heaviest glossy photo paper that I have found that is compatible with
my printer. I cannot vouch for its longevity, but it is supposed
to be equal to the Epson brand of the same type of paper which is not
as heavy as the Inkjetart paper. I consider this paper just
barely heavy enough to use for the cards without adding a
backing. None of the cards I have made so far have bent or
creased even when handled by kids (ok, careful kids).
THE
INSTRUCTIONS ON
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