User Guide

490 Series Microscope
AmScope Proprietary Page 56 of 64
Field of View and Working Distance
Field of view is how much of the specimen you can see
through the eyepiece. The linear field of view of the eyepiece
is divided by the magnification of the objective. The higher the
magnification, the smaller the field of view.
Working distance is the distance between the
bottom of objective lens and the stage. You
change the working distance when you use the
coarse focusing knob.
Together, working distance and field of view
determine how much of the specimen you see
and how closely.
Filters
Optical filters selectively transmit light of different wavelengths.
Blue filters compensate for low light levels in a brightfield application. (Like
dry layer blood analysis.) With low light, you see a yellowing effect. The blue
filter brings the light back to a more natural white light.
Green filters optimize the performance of achromatic and plan achromatic
objectives. When using phase contrast the best images are often produced
in green light.
Yellow filters compensate for blue images. The yellow filter brings the light
back to a more natural white light.