Changing the Pixel Size value directly affects the accuracy of your results. In some cases, you can use the same Pixel Size value for the entire measurement process. However, it is quite common to change the Pixel Size value depending on the feature type, feature size, and accuracy requirements. Internally, PC-DMIS Vision makes the necessary adjustments to accommodate changes to the Pixel Size value.
Focus accuracy is particularly affected by the Pixel Size value. The smaller the Pixel Size value, the higher the focus accuracy. Measurements in Z are almost always done at the smallest Pixel Size value.
Magnification is calibrated through "Field of View Calibration" and adjusted for optimal measurement of your feature via the "Probe Toolbox: Magnification tab".