Well, I had another try. Again I got lucky with a clear patch of sky in the west about an hour after sunset. This time I took several image sequences and the image above was made by stacking 8 images together. The sky is getting a little darker now the comet is a little higher and can be seen longer after sunset. There are a number of stars in the image now. Again shot with a 300/4L lens on an EOS 7D. Each exposure was around 2 seconds at f4 and ISO 3200.
Here’s a second sequence: