I opened up around 20:50 having researched what the issue could be with filter offsets, it was backlash in the focuser, a few settings in the software sorted this. So I re-ran the autofocus runs to determine offsets. I imaged the Iris Nebula and the offsets seem to have worked, I'm still not convinced that my guiding is optimal so that still requires experimentation.
Peter had done a great job tidying up around the battery and joined me around 21:00, Rachael and Jonny also arrived not long after with their Skywatcher gear.
We had a surprise visit from Mark Thompson DSc who co-presented Stargazing Live among many other TV shows, he was travelling back to Norfolk from Edinburgh. Rachael had been in contact with him via Twitter. He arrived around 02:50 and stayed until around 04:20, he was impressed with our setup and it was great to chat to him and he gladly shared his wealth of experience. I closed up around 04:50 and was treated to beautiful purple twilight on the way home.