Table 2.

NA values and measured optical resolutions for compound assemblies using DOs of different models (Fig. 1g) and the ‘standard version’ MO (Table 1).

DO magnification and model	×5 Olympus MPlan N	×4 Olympus MPlan N	×2.5 Olympus MPlan FL N	×2 Mitutoyo MPlan Apo
Diameter of the target zone	4.8 mm	6 mm	9.6 mm	12 mm
NADO given by the manufacturer	0.1	0.1	0.08	0.055
NAeff of the compound assembly	0.48	0.48	0.48	0.43
On-axis lateral resolution	1.0 ± 0.1 μm	1.1 ± 0.2 μm	1.4 ± 0.1 μm	1.5 ± 0.1 μm
On-axis axial resolution	35 ± 1 μm	37 ± 3 μm	42 ± 2 μm	51 ± 3 μm
Distance between MO and DO axes for off-axis measurements	2 mm	2 mm	3 mm	4 mm
Off-axis lateral resolution	1.3 ± 0.1 μm	1.4 ± 0.3 μm	1.6 ± 0.2 μm	1.8 ± 0.2 μm
Off-axis axial resolution	46 ± 2 μm	45 ± 2 μm	48 ± 1 μm	54 ± 3 μm

The resolutions are expressed by the full width at half maximum (FWHM) of 0.51-μm fluorescent beads (Bangs Laboratories, FC03F) measured (mean ± s.e.m.) from the acquired images. The image scale for each different configuration is individually calibrated using 20-μm fluorescent beads (Sicastar-greenF, 42-00-204)