My original picture for today was actually a 2-minute shot of Mars. Without a horizon for reference (it was almost overhead) Mars and the stars around it were just coloured streaks across the frame with no context. The hall light has been on my list of things to take a shot of at some point, so I decided to fall back on that as my alternate picture.
I left the camera on 100ISO, and shot this one at f/11.0, 1/60 of a second - purposely underexposed. I upped the exposure and contrast very slightly, cropped the picture, converted it to B&W with a gradient overlay and then painted out a bit of the overlay where the glass ball captured a little rainbow. Finally I applied a subtle un-sharp mask to bring out the detail a bit.