User Guide

490 Series Microscope
AmScope Proprietary Page 24 of 64
2.19 Using a Phase Contrast Kit (Optional Accessory)
Brightfield Phase Contrast
Some specimens may offer little in the way of color-variance or opacity and can
appear essentially invisible when using basic, transmitted light. Phase-contrast is a
technique used in microscopy to enhance the contrast of an image, when observing
a specimen which offers little contrast in normal bright-field conditions.
Light waves have several
measurable components,
the most-common of which
are length, frequency and
amplitude. While length and
frequency translate into the
color of light we see,
amplitude translates into
brightness.
One component that we do
not perceive is phase, which
can be described as “how
much of the wave’s cycle
has elapsed at a given
time.”
If you imagine light as a
small dot (a photon), moving
along the cyclical arcs of a
light wave, the phase is
current position of the
photon, relative to the
wave’s entire cycle.