Ovulation tests & a good reader?

So I'm taking ovulation tests and the glow reader is so wonky. It's hard to capture and yesterday I tried twice and once it said positive once it said negative on the SAME test. Which I do not think is positive.

Also I notice with these tests both the control & the test line get darker over 24 hrs. So when is the best time to take a picture with an opk reader? As I look at them now the test from the 31st is looking a lot closer to positive than it did in the first 5 min but I don't know.