Best Practices
Both
Optimize Focus
and the
Focus Feedback
use the same procedure for testing the current focus. They consider
various sub-regions of the image.
Follow these guidelines to maximize the performance of
Optimize Focus
and
Focus Feedback
:
l
Use a focus target (such as the one supplied with this Reference Manual) that includes high-contrast features
and is big enough that if ills at least a 100x100 pixel region in the center of the field of view at the desired working
distance.
l
Avoid floppy pieces of paper and make sure the target is perfectly flat.
l
Make sure that the target is perfectly perpendicular to the optical axis of the reader.
l
Make sure that the rest of the field of view, such as the part not covered by the focus target, does not contain any
high-contrast features. For example, if you would ideally fill the entire field of view with a white card or sheet of
paper (no shadows), position the focus target in the middle.
l
The supplied 120x120mm focus target is appropriate for typical working distances. If you use such a working
distance that the target does not completely fill the image, make sure that there are no high-contrast features
visible outside of the target (see previous bullet).
Note
:
l
If you use the focus feedback indicator to adjust a manual focus lens, you must apply power to the reader
before you remove the cover. If you remove the cover before applying power, the internal illumination will
not function.
l
If you use a Liquid Lens, make sure that the cover is mounted and connected before you apply power. If you
attach or remove the front cover while the reader is powered, the focus setting is lost.
45
Setting Up Your DataMan 370 Reader
