I harvest when i can see amber trics by eye, no microscope needed when it gets amber time and although some like to harvest cloudy i reckon most prefer amber or at least a certain percentage amber. I mostly go of seeing amber trics and what the bud looks like, if its swollen all over and the hairs have withered and receeded then its good. Most i grow has almost 90percent withered red hairs and swollen calyxs when ready and amber anyway, at this point whole groups of trics have turned amber, amber gold is the best!lol!
Take a plant with 5 buds, harvest each one one week after with the fith bud being the last and way past harvest time, roll a joint of each and see what high you prefer. Peace