I've noticed there there is all sorts of dusts and fingerprints on the lenses, and its making the projected image ugly. Is there any good way to clean the fresnels?

theres plety of info if you use the search engine(and a ehlpe is to use google and enter your search term, then add site:lumenlab.com to it.... anyway, I used tiny paintbrushes for the grooves, use canned air first ,rinsed it with distilled water(NOT tap water...will spot) to get rid of any big scratchy particles,then microfiber cloth( 3m lens cloth) and plexi/opti cleaner from home depot or somewhere

I don't find the search engine particularly helpful, seeing as how I type in "cleaning fresnels" and I get 20+ pages with the words cleaning and fresnels, anywhere but not together on the page. Anyway, thanks for the advice on cleaning.

try this search. "clean fresnels" , make sure you use the quotes.