Method: each detector/ camera images an multi-wavelength fluorescent source. This can be performed using the internal light sources and a fluorescent bead sample or an etched fluorescent pattern covering the field of view. A minimum standard would be recording the field of view for each high resolution objective over the widest field of view with all available excitation options (i.e. lasers or filter cubes).
Justification: this allows monitoring of objective quality. Comparison of chromatic shifts over time for each objective will identify any new aberrations in the system (eg damaged or unclean objective). The data can be used for post acquisition correction if required, and therefore improves the quantification of data from across the field of view, improving data reliability.