National Instruments NI Vision NI 17xx 用户手册

Figure 3-1 illustrates horizontal field of view and working distance.

Figure 3-1.  Parameters of an Imaging System

For example, if the working distance of your imaging setup is 100 mm, and 
the focal length of the lens is 8 mm, then the field of view in the horizontal 
direction of a smart camera using the VGA sensor in full scan mode is

(3-2)

Similarly, the field of view in the vertical direction is

(3-3)

Based on the result of Equations 3-2 and/or 3-3, you can see that you might 
need to adjust the various parameters in the FOV equation until you achieve 
the right combination of components that match your inspection needs. 
This might include increasing your working distance, choosing a lens with 
a shorter focal length, or changing to a high resolution camera.

1

Horizontal Imaging Width

2

Working Distance

3

Horizontal Field of View

3

2

1

0.0074 mm 640

×

100 mm

×

8 mm

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59.2 mm

=

=

0.0074 mm 480

×

100 mm

×

8 mm

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44.4 mm

=

=