Friday, March 29, 2013

More on Darkfield Microscopy

Darkfield microscopy requires a special stand containing a reflective mirror and light shielding plate at a specific angle. The inverted hollow cone is projective of the desired image at an oblique angle. This process is the same for both stereo microscopes and standard compound microscopes. 

Good specimens for darkfield microscopy are those close in value to their background images. Small aquatic organisms and cells are ideal for such microscopic lighting technique. Specimens preferred for use with brightfield lighting are not recommended. Other ideal specimens for darkfield microscopy under a stereo microscope include bones, fibers, yeast, and hairs.

Illumination from brightfield lighting involves blocking out central light rays along the central axis. Blocking these rays allows for only oblique angled rays to strike the specimen resulting in a hollowed cone illumination of the desired specimen.

In darkfield lighting, contrast is greatly enhanced by the lighting technique at hand. Highly oblique light rays, diffracted by the specimen and yielding first, second, and higher diffracted orders at the rear focal plane of the objective, proceed onto the image plane where they interfere with one another to produce an image of the specimen.

We recommend our 1600X Darkfield Compound 9MP Digital Siedentopf PLAN Microscope
with 4 PLAN objectives and darkfield condenser. 

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