Results for: 'microscopy'
MMG195A Lecture 17 - Principles of Microscopy
Lecture 17 for MMG195A, Spring 2020 semester. By Dr. Menelaos Symeonides.
Transform - diffraction - transform - image
Spatial information in the rear focal plane.
Zero order has no information
Spatial information is encoded in the diffracted rays.
Spatial deteil vs acceptance angle
Acceptance angle of objective must be wide enough to collect at least first order diffracted rays
See back focal plane using telescope
The rear focal plane of the objective can be observed using a telescope insert into the eyepiece tube.
Diffraction pattern in the transform plane
Demonstration of diffraction patterns in a test object - (Diatom test slide).
Spatial filtering in the transform plane
Using a small aperture slider to remove diffracted orders in the transform plane eliminates detail in the image plane.
Acceptance angle vs working distance
Working distance decreases with increasing acceptance angle.
Numerical Aperture vs useful magnification
A quick estimate of useful magnification:
N.A. X 1000.