This Teapot example shows what can go
The separation between the two points of view affects the way you perceive the
Too small a gap between the points of view and there is a reduced stereo effect.
Too large a gap and your brain starts to produce an image that looks smaller than it
ought to be. Resulting in big objects that look like toys.
In this example I used two 35 mm cameras mounted
landscape-wise, side by side on a bar. A standard setup and quite easy to achieve, with
However, I was quite close to the teapot as I wanted it to fill the frame.
The bar had a slot which allowed one camera to slide along. It was possible to place one
camera body behind the other so that the separation between the lenses was reduced.
This would, I thought, in turn reduce the toy like look to the teapot.
Yes. It did reduce the toy effect, but it introduced another more destructive
element. This is something that is present all the time when you focus a single camera
or move a stereo camera.
The fault I introduced was a difference in the size of the object in each image.
The camera at the back produced a smaller image than the camera at the front.
Simple when you think about it.
If you are near to something it occupies more of the field of view.
So from a cameras point of view the object is bigger in the view finder. It occupies more
of the film emulsion.
A similar effect occurs when you focus a camera with a view finder that looks through
the lens. You can see the change in image size as you change focus from near to far,
though the image may not be sharp.
The lens is being moved relative to the film ... so an image occupies more or less of the