Thank you so much for your answer.
I think we can try
Move the pattern closer until it is recognized once. You can then move it back a bit and it can still be detected.
One more question:
If Operating Distance is 750mm - 5000mm, can I expect to detect within those range? After remembering the size and pattern, can we move the calibration board at 5000mm and the board must be detected?
The background of this question is that we want to verify the calibration results by checking error across detection volume after finishing intrinsic parameters calibration.
