- - Used in adaptive optics and
optometry, uses a lens array to measure aberrations.
- - The formation of interference fringes
due to the overlap of similar gratings. The fringes produced are greatly magnified in comparison to the size of the actual grating spacing, so minute variations in one
grating result in large changes in the moire fringes made with a second grating. Moire fringes are extremely useful in comparing a set of fringes that has been misaligned
in some way (projected onto the surface of a mirror to find aberrations, or a specimen for contouring) with a reference grating. Used to monitor small displacements, also
used to measure deviations into and out of a reference plane (topographical imaging, contouring, 3D imaging, etc). The moire effect creates a readily observable pattern
that changes as the alignment of the gratings is altered.
Moire demo - Fringes (the thick black and white bands) are
created by overlapping spherical patterns and change greatly with respect to the motion of the smaller sphere.
Andrew Davidhazy-Articles and
photos for high speed, Schlieren, stroboscopic photography, etc.
Schlieren Demo - Basic Schlieren setup, cool pictures.