M48 Hertzsprung–Russell diagram
A jab at being scientific. I tried to make a Hertzsprung–Russell diagram from an older Messier 48 open cluster image I had taken with regular LRGB filters.
The linear, calibrated B and G channel images (4x5min integration time each at full moon) were processed in PixInsight to flatten sky gradient, extract non-saturated stars (position, size, brightness) and to get a reference Tycho data. These data files were correlated in Excel to get an offset from measured to known magnitudes.
The HR-diagram is simply a scatterplot of V magnitude over B-V magnitude. I ended with 809 data points with pretty decent linearity.
I also wrote a blog posting about the process.