A zoom lens for digital image capturing apparatus is a shared lens of digital
static
cameras and digital video cameras. It contains three lens groups. From the object
plane to the image plane, the first lens group has a negative refractive power,
the second lens group has a positive refractive power, and the third lens group
has a positive refractive power. As the focal length of the zoom lens changes from
long (telescope) to short (wide-angle), the second lens group moves from the object
plane to the image plane. The third lens group and the first lens group move with
the second lens group.