For computer modeling:

Freeware:  From NIH  Image program (available for MACs and PCs on web)

Necessary Optics --Each experimental set up should include:

Laser source
Diverging lens to spread beam as it encounters object
Resolution chart for object
Converging lens
Screen

Filtering is accomplished with:

Iris aperture (low pass filter)
Glass slide with 1mm gold dot painted on it (high pass filter)
2 index cards (for single orientation filtering)