User`s manual

108  Technical Specifications Genie Monochrome Series-GigE Vision Camera
Primary Points in a Lens System
Magnification and Resolution
The magnification of a lens is the ratio of the image size to the object size:
h
h
m
'

Where m is the magnification, h’ is the image height (pixel size)
and h is the object height (desired object resolution size).
By similar triangles, the magnification is alternatively given by:
OD
f
m
'

These equations can be combined to give their most useful form:
OD
f
h
h ''

This is the governing equation for many object and image plane
parameters.
Example: An acquisition system has a 512 x 512 element, 10m pixel pitch area scan camera, a lens with an
effective focal length of 45mm, and requires that 100m in the object space correspond to each pixel in the image
sensor. Using the preceding equation, the object distance must be 450mm (0.450m).
OD
mm
m
m 45
100
10



)450.0(450 mmmOD 