when to harvest my sativas!?

i have 4 plants, 3 that are looking like theyre about to end their flowering... could anyone help me out with an estimated harvest time for these puppies? any guesses would be great... first time grow and i have no idea. theyve been flowering for about 7 weeks, maybe 8. the strain is easy sativa.

any guess would be great! thanks

do i need more close up pictures? sorry if it is hard to tell from these, my phone camera cant take good close ups. let me know what to do to help determine how much longer!

can anyone give me a good guess as to when they think it might be?

Yeah the pictures aren't too clear.

buy a microscope and check out the trichs...