Unit: Perceived Microns [pµm]

The unit "perceived" is calculated from Photometric Stereo Topographical maps from the surface slopes and facets that are visible to the camera and calibrated using a 540µm artifact.

Our optical system works best for surfaces with a texture amplitude of 0-1500 (1.5mm) microns with homogeneous reflectivity- in this range the Aesthetix measurement system is linear and obtains results highly correlated to other systems.

Note that as the texture gets bigger the measurement system becomes less linear-this is because the peaks and valleys of these large structures are less in focus, we also capture shadows in deep valleys that make it difficult to resolve the topography in those areas.