Omron STC-S133MIP Series Product Specifications And User's Manual page 32

Distortion compensation settings
KNOT K0 (optical center) to KNOT K13 (edge) are the compensation points for the distortion compensation.
When set the greater value, the distortion is reduced. When set the smaller value, the distortion is extended.
There are four types (A, B, C and D) of the compensation points are available.
Distortion compensation OFF
STC-S133MIP
Product Specifications and User's Guide
Distortion compensation ON
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