When do you guys think it will be ready for harvest?

Been flowering for 9 weeks now! Most of the hairs are red/brown. But the trichomes are all white. I only have a 8x magnifying glass, is that enough to spot the amber ones? I mean, I dont see any amber, only white.

Do you recommend I maybe harvest one branch now, and wait with the rest to see if they get any more amber?

I'm worried that they are turning amber but the magnifying glass not beeing strong enough to see it...