Table 1. The numerical aperture and solid angle of light collection for different microscope objectives.

Objective	Numerical Aperture (NA)	Solid Angle Ω (sr)
5 ×	0.12	0.045
10 ×	0.25	0.200
20 ×	0.4	0.525
50 ×	0.5	0.842
50 ×	0.75	2.13
100 ×	0.85	2.97