Autofocus - finally!
Ever since I installed my 4" Focuser on the Starfire, I was also using the Optec FocusLynx for remote focusing. It also offers a temperature compensation feature, but this requires some preparation I never took time to configure.
The high temperature differences we are currently experiencing during these nights make even the focus-stable Starfire shift in focus. This convinced me to finally configure the temperature compensation feature. Using the wizard for this, the setup procedure was easier than expected: Focus for first picture and save temperature and focuser settings. Then wait for a change in temperature of at least 5 degrees, focus again and save temerpature and focuser settings again. After that, the wizard calculates all necessary parameters and saves them into the focuser software settings.
Last night, I was able to test temperature compensation and what can I say? It worked like a charm - from 5 hours of lights I was able to take last night, all were focussed exactly to the point.
This is the result - NGC4535 with 4h39m of total integration time.