Difference Between Brightfield and Darkfield Microscope

Both bright field and dark field microscopes are optical microscopes that employ light to view a sample and magnify it, but the similarities end there. The working principle of both the microscopes is entirely different.

Optical microscopes employ visible light and a series of lenses to magnify the specimen and view it in detail. A bright-field microscope uses light rays to create a dark image against a bright background.

While on the other hand, a dark field microscope operates on the opposite principle of a bright field microscope, and the entire field of view appears dark when there is no specimen and once a specimen is placed, it appears bright over this dark background.

Bright Field Microscope Vs Dark Field Microscope 

differences between darkfield microscopy vs brightfield microscopy image
Image: Differences between Darkfield microscopy vs Brightfield microscopy image.
created with the help of biorender.com
ParameterBright FieldDark Field
Image FormationWorks on the principle of absorption of light. Light is focused on the specimen and it absorbs the light and the contrast image that is dark is viewed against a bright backgroundThe entire field of view appears dark when there is no specimen and once a specimen is placed, it appears bright over this dark background
Type of ImageDark image against a bright backgroundBright image against a dark background
Types of specimensFixed specimens are viewed and are typically stainedAll live specimens can be viewed even without staining them
Specimen PreparationIs complex as the specimen needs to be stainedNo need of a stain
Color of specimenAppears blur or dark (depending on the stain used)Specimen appears bright
Background of specimenBackground is brightBackground is dark
Types of condensers usedAbbe Condenser, Variable focus Condenser, Achromatic condenser.Abbe Condenser, Paraboloid condenser, Cardioid Condenser.
Extent of viewingIt shows the internal as well as the morphological structure of the specimenIt shows the external structure of the specimen
CostThey are inexpensiveThey are comparatively expensive
Opaque DiscNot presentPresent
UtilityIt is very easy to useIt is comparatively complex to use
Ability to study Minerals and MetalsThis microscope can’t  be used for the study of minerals and metalsThis microscope can be used to study minerals and metals

References

  1. http://www.differencebetween.net/science/differences-between-bright-and-dark-field-microscopes/
  2. https://www.microbehunter.com/what-are-the-differences-between-brightfield-darkfield-and-phase-contrast/
  3. https://www.spiedigitallibrary.org/journals/journal-of-biomedical-optics/volume-19/issue-10/106002/Real-time-brightfield-darkfield-and-phase-contrast-imaging-in-a/10.1117/1.JBO.19.10.106002.full?SSO=1
  4. https://public.wsu.edu/~omoto/papers/Fig1.html
  5. https://everythingwhat.com/what-is-the-difference-between-bright-field-and-dark-field-microscope

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