Expt 1: Focal Length Parallel light rays from far away light source Lens # 1 Screen Move lens until the image of light source appears on the screen

Light Unit Plastic ruler is on the light source! mm Face view mm The manual instructs students to use the plastic ruler to measure the source size. They immediately rush to a meterstick. I always laugh. Ha, ha, ha! Plastic ruler is on the light source! Inner circle diameter: 10 mm

Expt 4: Depth of Focus (Field) Top view Aperture Light Unit Lens # 2? Move screen Many students get lost on what the manual is trying to instruct. They need to measure and compare the range of good focus for two different aperture sizes. Find the range (depth) of good focus

Expt 5: Spherical Aberrations and Curved Focal Plane Top view Aperture Screen Light Unit Lens # 1 Move lightly Aperture Peripheral Mask Central Mask One of the hardest experiments. I would suggest to do this experiment the last. The effect we see are sometimes small for unknown reasons. Students need to be pointed out on what changes they are seeing and why they are worth noting! Examine image qualities

Expt 6: Chromatic Aberration Top view Aperture Roscolux Filters Light Unit Lens # 2? http://www.rosco.com/images/filters/roscolux.jpg A lighter color filter usually passes through green/yellow spectrum which result in less dramatic difference in focus point. But #27 (4% transmission) and #83 (4% transmission) filters may be too dark in a brighter room... You could try #80 Primary Blue (9% transmission) and #26 Light Red (12% transmission). Adjust screen #27 Medium Red #83 Medium Blue Compare the position of good focus