Fig. 14From: Round robin comparison study on the form measurement of optical freeform surfacesRMS values of difference maps for the concave toroidal specimen. The RMS values of the pointwise differences of the following four measurements are shown: 1: Mahr TWI, 2: Mahr MFU, 3: IPP MFU, 4: NMIJ UA3P. The value of row i, column j shows the RMS value for the pointwise differences of measurement i and measurement jBack to article page