What was your assessment of the seeing. Your imaging time was closer to John's. He said the seeing was good, I thought it was mediocre. I'm wondering whether it had something to do with aperture size. I used to get good seeing more often when I was using the 10"D-K.
I thought that maybe I was getting some temperature gradients from the mirror to ambient, but it had been cooling for a few hours before I started imaging - I don't have a temperature readout, but it seemed quite stable (ie fast, consistent seeing with no obvious heat plumes in the out of focus image).
This didn't change over the course of about 1-1/5 hours.
