The light or better the remainder of the light was awesome and the sky was about to explode - which it actually did just a couple of minutes after I took those pictures but more of that later.
I was walking the dog that evening and only brought my fast 50 with me (translation: Canon 50mm f/1.4) - no tripod of course. The light level was so low I had to shoot fully open at f/1.4 and ISO 6400 to get a shutter speed of 1/40. To create a wide-angle panorama with a 50mm I shot a total of 17 frames and stitched it together using Photoshop CS5.
I adjusted the white-balance to reduce the color temperature even more - (I shot in the tungsten setting as always for night photography
- and used the built-in noise-reduction of Lightroom 3 on the 17 RAW files before exporting them to smaller JPG's to process in Photoshop. I do this most of the time for big panoramas to save time and to see if it actually works - it doesn't all the time and that's a optimistic statement.
I can still process the full-res RAW's the same way later if I want to - I didn't feel like for that one as I'm generally not patient enough to wait 4 hours.
It was a fairly quick process in Photoshop - thanks to the small JPG's. After I cropped the produced panorama I created a black-white layer using the awesome Silver Efex Pro 2
by Nik Software using a green filter and blended it using the Soft Light option to get more drama.
15 minutes after I took that shot a really bad rainstorm hit the area (and me without rain-protection), almost killing my 50mm lens. My Canon 5D Mark II is weather sealed but I forgot that the 50 was not. I usually don't mind the rain and keep shooting but the autofocus in the lens stopped working after a few minutes - that was the last time I shot with that lens in the rain, btw.