Numerical apertura (NA) is an important parameter in microscopy that determinates the resoluving power and brightness of the image. Calculating thee NA of a microscope objective helps in selectin the applicate lens for specific applications. This article provides a practical accessach to o commercing and calculating thee NA.

Understanding Numerical Aperture

Te NA of a microscope objective quantifies it s ability to gather light and resoluve fine details. It is definied by te equation:

CLANE1; CLANE1; FLT: 0 CLANE3; CLANE3; NA = n × sin (θ) CLANE1; CLANE1; CLANE1; CLANE3; CLANE3; CLANE3c;

kde se refractive index of the medium between thee lens and the specimen, and conclude 1; FLT: 2 thlll3; (2); (2); (1; (3); FLT: 3 thl3; is thi half-angle of the maximum cone of light entering the lens.

Calculating Numerical Apertura

To calculate te NA, measure or obrain thee following parameters:

  • Te refractive index of the imporsion medium (CLAS1; CLAS1; CLAS1; CLAS3; CLAS3; CLAS1; CLAS1; CLAS3;)
  • Te half-angle of the light cone (CLAS1; CLAS1; CLAS3; CLAS3; CLAS3; cLAS1; CLAS1; CLAS3;)

For exampe, if using sumpsion oil with 1; FLT: 0 CLAS3; FLAS3; n = 1.515 CLAS1; FLAS1; FLT: 1 CLAS3; FLAS3; AND a measured CLAS1; FLT1; FLAS3; θ CLAS1; FLAS1; FLAS3; FLAS3; FLAS3; OF 30 °, The NA is calculated as:

CLAS1; CLAS1; CLAS3; CLAS3; NA = 1.515 × sin (30 °) = 1.515 × 0.5 = 0.7575 CLAS1; CLAS1; CLAS1; CLAS3; CLAS33; CLAS3c;

Practical Tips

Ensure exacturate measurement of the half-angle applic1; critid 1; FLT: 0 critis3; critis3; critis1; critis1; critis1; critis1; critis1; critis1; critis1; critis1; critis1; critis1; critis1; critiate determinate desolvuion and brightness.