Fig. 6From: Round robin comparison study on the form measurement of optical freeform surfacesRMS values of difference maps for the two-radii specimen. The RMS values of the pointwise differences between the following five measurements are shown: 1: USTUTT TWI, 2: PTB TWI, 3: Mahr TWI, 4: Mahr MFU, 5: IPP MFU. The value of row i, column j shows the RMS value for the pointwise differences between measurement i and measurement jBack to article page