Day 50 of flowering....When do I harvest??

This strain i'm growing has an apparent 55-60 day flowering period, but I don't have access to a magnifying glass powerful enough to look at the trichs....I want to get the most out of her, so:

How do I know when it's peak harvest time just by using a weak 'glass? (1st pic taken with 3x)

if those pics were taken today you might have 75 -90 days do you now the strain or is it a bag seed. if you cant get a 30x magnifier from radio shack for 10$ wait till about 90% of hairs turn from white to red. on entire plant not top cola