hard modes work aswell

thats one of many sites where people enter which windows are open (= which content gives increased light)
http://www.reddit.com/live/tlfmtjl4fteo

feeble = 1
gentle = 2
bright = 4
brilliant = 6
blinding = 12
newborn star = 16


hard mode primals with bonus spend 4 light (bright) and doing expert dungeons with bonus gives 12 (blinding)
I think that are the easiest things to farm it