Assume an average eye-seperation of 65.5 [mm] (Ferwerda [1990],
page 220,
section 21.8)
The eye lens separation changes due to the turning of the lenses
when converging to near by objects. The effect can be seen below, the
eye lens separation reduces some 4.5% for objects at 250 mm
distance (compared to objects at infinity).
The deviation
on the eye's retina,
due to an object at a distance
of focused distance, is (this
includes the above changing eye lens separation):
All the homologous points should be on the same
height
in both
pictures
There should be no
objects on the edges of the pictures which are
closer
by then the stereo window distance (w). These would cause window
violations.
The On-Film Deviation (d) is determined by the
parallax (p) and Fc (d=Fc*2*tan(p/2)).
The camera base (b0) is (from stereo window
distance and infinity):
b0 = d*(w*1000-F_{c}/2)/F_{c} [mm]
This is Special case No.
2 in this link.
The stereo window distance (w)
is
appr.
half
the hyperfocal distance (Ferwerda [1990],
page 22, section 1.4).
The minimum diaphragm is (assuming 2.25' point acuity, 45 cm view
distance, 36 mm film, camera on infinite and halving f_{min}
due to stereo photo (Ferwerda [1990],
page 81, section 8.4)):
f#_{min} = 3*F_{c}^{2}/w (Hawkins [1980], page 70-71)
The pictures need to be fairly sharp in the range of w to
33w (Ferwerda [1990], page 116,
section 10.12). This
relaxes
the above f_{min}-boundaries with one stop with a
camera's focused distance at 2*w (based on own research).
The convergence distance (c) should be
bigger than (to
minimize the keystone
effect):
c >= 25*n_{h}*b0/F_{c} [mm] (Ferwerda [1990],
page 99, section 9.7)
Number of depth size between stereo window distance and infinity:
z
= p/stereoacuity [-] (Ferwerda [1990],
page 236, section 24.2)
With b0: distance between cameras
[mm] e:
distance between the eyes [mm] F_{c}: focal
length camera [mm] f#_{min}: minimum diaphragm number n_{h,v}: horizontal or vertical CCD/slide
size
[mm] w:
stereo window distance [m] p:
parallax [°] z:
number of depth step [-] d:
deviation (ODF: On-Film Deviation) [mm]
A stereoscopic subject finder
The stereoscopic subject finder.
The distance between the centers of the two finder holes: dfh = e -
65*z/(w*1000) [mm]
The size_{h,v} of the finder holes: sfh_{h,v} = n_{h,v}
*
z/F_{c} [mm] (Ferwerda [1990],
page 90, section 8.10)
Barrel (when negative; pincushion)
strength within PSP,
when compensating pictures made with Fujifilm FinePix 2600Zoom
Barrel (when negative;
pincushion)
strength within PSP,
when compensating pictures made with Fujifilm FinePix E510
check that homologous points in each picture are not
rotated from
each other, otherwise compensate (with help of AnaBuilder or SPM)
check that the scale of each picture (best checked with [virtual]
surfaces that are really perpendicular to the direction the picture was
take) is the same, otherwise compensate (with help of AnaBuilder
or SPM)
all the homologous points should be on the same height
in
both
pictures (with help of AnaBuilder or SPM)
if there are no infinite points use a slightly smaller separation
of:
eyeseparation - (distancepicture/farthestobject_{act}*(eyeseparation/2))
[mm] (displaying/mounting to
farthest)
the separation between the two right sides (and left sides) of
the
photo
should be 0.2 [mm] smaller than the distance between the two most
closest homologous points.
Ferwerda's guidelines for camera
configuration
A more general calculation is at another
page.