Making a Fresnel Lens for Solar Water Purification

[Pranav Jha]

i want to do a project on solar water purification. I just saw a video on purifying water using fresnel lens. However, i haven't found any information on how one can make a fresnel lens suited to the purpose. So, how does one make a fresnel lens?

 

[schip666!]

Take a regular lens and squish it into a thin plate by removing all the excess material inside... A Fresnel is pretty much just the individual curved sections of a lens surface.

I've never heard of anyone making them by hand, but you should be able to find largish plastic ones for sale pretty easily. I've think I've seen up to 8x10" sheets in office supply stores for page magnifiers.