Man Helmut, nice plants, love all your pix especially the trichomes. But. It looks like you have some time left my friend. Just as posted above, the plant as a whole is how you judge ripeness. By this I mean an overall look to the plant, the trichomes, the pistils, the color, just soo many things. Next time take the whole plant pics without the HPS on. The cola looks like it's gonna swell some more. I'm not sure but do I see a bunch of white pistils? I think so.
Your lookin good. Don't rush it.
Good luck
Polo