Figure 4-1.—Vertical photograph.
Figure 4-2.—Tilt angle.
to the ground, is 90 degrees (fig. 4-3). Oblique images
may be anywhere between 0 and 90 degrees, do not
have a uniform scale, and are divided into two
subcategories—high oblique and low oblique. The
horizon is visible in high obliques but not in low
obliques. This can be remembered easily by thinking
high sky, low no.
axis) and the horizontal is called the CAMERA
DEPRESSION ANGLE; straight out, parallel to the
ground, is 0 degrees, and straight down, perpendicular
Figure 4-3.—Camera depression angle.
4-2
