Numerykal apertura (NA) is an important parametr in microscopy that determinates thee resolving power and brightness of thee image. Calculating the NA of a microscope objective helps in selecting thee approviate lens for specific applications. Thi s articlie provides a practical approvach tam understang and calculating the NE NA.

Understanding Numerical Aperture

Te NA of a microscope objective quantifies it ability to o gather light and d resolve fine details. It i s definite d by thee equation:

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where message 1; index of thee medium between thee lens ande the specimen, and beit1; index1; fLT: 2 message 3; θ message 1; index1; fLT: 3 mediatis3; is thee half-angle of thee maximum dem cone of light entering thee lens.

Kalkulating Numerykal Apertura

Tu calculate thee NA, measure or obtain thee following parameters:

  • Thee refractive index of thee inmersion medium (Johann1; FLT: 0 presenta3; Yann3; n pretendal; Yann1; FLT: 1 pretendation 3; Yann3;)
  • Thee half-angle of thee light cone (Johann1; Yann1; FLT: 0 Yann3; Yann3; θ Yann1; Yann1; FLT: 1 Yann3; Yann3;)

For example, if using inmersion oil with simple1; gif1; FLT: 0 supple3; n = 1,515 supple1; gify1; FLT: 1 supple3; gifl3; and a metriured supple1; gifl1; Gifl3; θ supple1; FLT: 3 supple3; gifl3; of 30 °, the NA is calculated as:

BEA1; BEA1; FLT: 0 BEA3; NEA3; NEA31,515 × sin (30 °) = 1.515 × 0.5 = 0.7575 BEA1; BEA1; FLT: 1 BEA3; BEA3;

Klepsydra praktyczna

Ensure cisilate measurement of thee half-angle indif1; indiv1; FLT: 0 mea3; enti3; θ mea1; indiv1; FLT: 1 measurement 3; indiv3; using appropriate tools. When using different inmersion media, adjuss te refractive index accordingly. Hiper NA values generally indicatte better resolution and brightness.