Spot on with your advice

I’ve posted a much better effort on my member’s page. With my first go, I thought stacking and sharpening a load of images (a la planetary imaging) would help things, but I think it actually blurred the spectrum – and the bit depth was 8 bit anyhow. This time I was careful with focusing and made sure the exposure wasn’t too high. I think the result is much better. Unfortunately the ADU of my camera is 14 rather than 16 bit, so there’s not quite as much data as there could be.