108 THREE-DIMENSIONAL PHOTOGRAPHY
now has a far more definite modeling than in the first. However,
the pointed shadow beneath the chin is about the same as in the
first and is not at all satisfactory. In short this is better than the
first, but not much.
Fig. 7-3.Figure 7-3. The light was held, freehand, about 30 inches from
the camera, above and at the right. It was fired by an extension
cord and is typical of “extension flash.” Note that while the left
ear and cheek are in deep shadow, the face modeling is far better
than in either of the others, and that even in the flat, the face
appears to have more roundness than in the first two. Compare
the lips with those of the other two. The modeling is far better.
In short, although the total relief of the head is not greatly altered,
the modeling of detail grows as the lighting becomes more angu-
lar. This is in direct accord with the visual effect, as all portrait
photographers and all artists know. Light affects stereo quality
simply because it affects visual quality.
These exposures were made under average amateur conditions
by an amateur stereoscopist of average experience to avoid any in-
fluence which might result from professional technique. They
were made with the Rolleidoscope with the Kalart Master gun
and extension, using F bulbs and Plus X film.
Pink Eye.-When the flash is almost in line with the camera lens
a peculiar effect results, one in which the pupils of the eyes have
an unusual pink coloration. Two explanations have been offered,
both similar. One is that the light reflects at the retina and fills
the eye with a reddish glow, the other is that a fluorescence is ex-