Magnification And Resolution - Dalsa Piranha 3 Series User Manual

66
lens su rface to the second focal point. The object distance (OD) is the d istance from the first
principal point to the object.
Figure 20: Primary Points in a Lens System

Magnification and Resolution

The m agnification of a lens is the ratio of the im age size to the object size:
m
By sim ilar triangles, the m agnification is alternatively given by:

m
These equ ations can be com bined to give their m ost u sefu l form :

h
h
Example: An acqu isition system has a 512 x 512 elem ent, 10m pixel pitch area scan cam era,
a lens w ith an effective focal length of 45m m , and requ ires that 100m in the object space
correspond to each pixel in the im age sensor. Using the preced ing equ ation, the object
d istance m u st be 450m m (0.450m ).

10

100
03-032-10216-06
All manuals and user guides at all-guides.com

w here m is the m agnification, h' is the im age height
h

(pixel size) and h is the object height (d esired object
h
resolu tion size).

f
OD

f This is the governing equ ation for m any object and

im age plane param eters.
OD
m 45 mm
 
OD 450
m OD
mm ( . 0 450 m )
Piranha 3 User Manual
Teledyne DALSA