I had a tip off that it might be possible to adjust the exposure time on a smartphone. Research told me that for Huawei I needed settings called Pro. I found that the maximum exposure time is 8 seconds. I pressed the camera against the double-glazed window to keep it still. I was amazed to see how much light in the dark sky was being picked up. It also seems to have picked up reflected light that I think must be coming back to the lens from the outer glazing. I will now need to wait for the clouds to part so I can find out if it is possible to photograph the stars.
