I recovered my damaged file, actually I found a back up I had forgotten about
To watch you must first right click on the link and select "save as"
The presentation is a little dated. The last NASA data I've read suggest they are now experimenting with at least 5 wavelengths. The video mainly focuses on 4.
It is interesting just how differently plants react to light. Photosynthesis is also only part of the story. There are also auxiliary pigments and their functions.
In addition, plants are not the only need to be considered. Certain wavelengths retard the sporation of the phytopathogen botrytis, while others trigger the sporation of the beneficial trichoderma fungus.
Anyhow, enjoy the lecture... its a good one.