First, are we 100% sure it's just dew, or could it be another substance? Second, in my experience, cleaning the sensor is not nearly as easy as it is made out to be in the video. I have tried that that exact approach and ended up with lots of residual specs and motes. Even with 99.9% isopropyl it was hard to not leave marks, the 91% stuff from the drug store left spots everywhere. Perhaps you all are much more talented at it than I am, but it's not that easy. What is ZWO's input?