Descreening filter

Descreening filter.

Principle:

- Fourier filtering makes it possible to modify certain undesirable frequencies of an object by inserting a suitable mask in the Fourier plane (or focal plane of the initial image).

- Thus, the image (or the different spatial frequencies that constitute it), is interpreted as a diffraction figure.

These measurements therefore require a collimated, but above all purified light source: this is why the Ovio Laser Torch (ref. 204 080), ready to use and pre-adjusted, is ideal for this type of technique.

Results:

Influence of the slit opening (reading on the micrometer screw) on the interference of spaced lines of different frequencies