Hi Greg, Three things: 1. I have noticed negative values in the LEF which I assume is connected to the negative phi2 and one would not make these values just 0 right?

1. We had a group collecting data in the dark and I noticed a lot of negative values in their data -- how should we handle this? -- it is the chlamy group? http://photosynq.org/projects/chlamy-group-bs-172-summer-2015

2. You had emailed me you could show this*(they have negative values for phi2 and SPAD) to me so I could show my students -- do you have a video? A good way to get a sense of 'normal' traces is by looking at normal values, and getting a sense of what a normal trace looks like. Then, go check out your wacky values and figure out... is this just a zero phi2 (biologically inactive) or did the user miss the leaf (which should be flagged and excluded). I'd be happy to show you what I mean so you can show the class.

Thanks again for always responding so quickly to all the emails. Sonya