I shot this on my Fuji x100, it was near pitch black in the woods. I was in Herefordshire, staying in a Yurt.
To get the lettering like this I built an iPad app using XCode on the mac, I made 4 images, one for each letter S, L, U and T. Then I got the iPad to display them in short succession with a black screen in-between.
I shot on BULB mode so I could leave the camera picking up light for as long as I want, this was probably open for about 10 seconds to capture this while I stood behind the tree moving the iPad.
I hope you enjoy the final result which was mildly tweaked in Photoshop using the LEGENDARY Exposure 3 plugin.