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Difference between revisions of "Light microscopy"
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→Depth of field: more
(→References: +EL) |
(→Depth of field: more) |
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==Depth of field== | ==Depth of field== | ||
*Abbreviated ''DOF''. | *Abbreviated ''DOF''. | ||
*DOF depends on the aperature (small is better). | |||
Relation to other parameters:<ref name=grayfield_dof>URL: [http://www.grayfieldoptical.com/depth_of_fieldfocus.html http://www.grayfieldoptical.com/depth_of_fieldfocus.html]. Accessed on: 27 May 2011.</ref> | |||
*Inverse relationship with resolution and brightness. | |||
*Related to contrast. | |||
*High magnification --> smaller depth of field. | |||
===Formula=== | |||
<math>DOF = { \lambda_o n \over NA^2}+{ n \over M \cdot NA } e | <math>DOF = { \lambda_o n \over NA^2}+{ n \over M \cdot NA } e | ||
</math>.<ref>URL: [http://www.microscopyu.com/articles/formulas/formulasfielddepth.html http://www.microscopyu.com/articles/formulas/formulasfielddepth.html]. Accessed on: 27 May 2011.</ref> | </math>.<ref>URL: [http://www.microscopyu.com/articles/formulas/formulasfielddepth.html http://www.microscopyu.com/articles/formulas/formulasfielddepth.html]. Accessed on: 27 May 2011.</ref> | ||
Where: | |||
*<math>\lambda_o</math> = illuminating light wavelength. | |||
*n = refractive index of the medium, 1.0 for air. | |||
*NA = numerical aperature (objective). | |||
*M = magnification. | |||
*e = resolution. | |||
==Kohler illumination== | ==Kohler illumination== | ||