Panasonic AG-3DP1G Manuel D’Utilisation

Page de 140
55
Chapter
4
Adjustments
and
Settings
for
Recording
What is convergence point adjustment?
What is parallax?
A human’s stereoscopic viewing takes advantage of 
the brain’s ability to process information from the left 
and right eyes of two images seen from their respective 
perspectives. The misalignment of the two images is 
called binocular parallax.
Mainly binocular parallax is used by 3D equipment 
to create the feeling of stereoscopic images. When 
shooting, the images from the left and right lenses are 
misaligned because of the difference in the positions of 
the lenses as well as in the directions of the optical axes. 
This misalignment (called parallax) changes according 
to the distance of the subject being shot (illustration at 
right).
If parallax is excessive, it is difficult to fuse the two 
images within the brain. This may produce a double 
image, create a feeling of strangeness, etc., causing 
eyestrain.
Limiting the parallax appropriately during shooting is 
important for comfortable 3D viewing.
 Are there guidelines for appropriate 
parallax?
There are two guidelines for parallax.
A
  Parallax: 3 % or less the effective width of the screen 
It is usually said that a parallactic angle within 1 
degree is preferable for comfortable 3D viewing. The 
parallactic angle, here, means the difference between 
the angle of convergence when a viewer watches a 
point on the screen and the angle when he or she 
watches an object popped out or recessed from the 
screen. A large parallactic angle makes it difficult for 
the viewer to perceive a stereoscopic image, causing 
eyestrain. 
Assuming that people view 3D images from a 
distance three times the effective height of the screen, 
a parallactic angle of 1 degree corresponds to 
misalignment of approximately 3 % the effective width 
of the screen. This leads to one of the guidelines for 
parallax, which is to limit horizontal misalignment to 
within 3 % the effective width of the screen.
B
  Parallax in depth: 50 mm or less 
Parallax in depth is created when an image from the 
right lens is displayed to the right and an image from 
the left lens to the left on the screen. 
If the value of this parallax exceeds the pupil distance 
of a viewer, it will cause eyestrain. 
In consideration of individual differences of viewers 
such as age and pupil distance, setting parallax to 
within 50 mm is preferable. 
Parallax in depth is related to screen size. For a 16:9 
screen, if the screen size is 77-type or less, limiting 
parallax to within 3 % the effective width of the screen 
means that parallax in depth will not exceed 50 mm. 
If the target screen size is 103-type, limit parallax to 
2.2 %. For a 200-type screen, limit parallax to 1.1 %.
How to operate this camera
The 3D assist function of this camera (page 56) provides 
a guide of distance ranges from the subject for achieving 
appropriate parallax. Referring to the guide, change the 
layout of the subject and check the parallax value (% 
effective screen width), using a monitor.
Convergencepoint
Left-lensimage
Right-lensimage
Parallactigangleindepth
Parallacticangleforpopout
•  Extreme parallax between left and 
right images is demonstrated in the 
illustration above.
Parallaxforpopout
Parallax: Approx. 3 % or less (any screen size)
Parallaxindepth
For a screen of 77-type or less
Parallax: Approx. 3 % or less
For a screen of 77-type or more
Parallax: 50 mm or less