Hello, Systems Engineer specializing in server virtualization and storage here!
I think most people in IT are the highly-analytical type. We enjoy taking complex problems and finding the solution. For me, I got started when I noticed that my portraits I was trying to take of my daughters really sucked compared to some that a professional photographer had taken. I wanted to know why and what was the difference in what we were doing. I'm a smart guy, surely I can figure this out. So that got me into SLRs and lenses and reflectors and now each shot is a bit of a technical riddle, but in an artistic and relaxing way at the same time. Its the same things that drew me to IT, but in a completely different way. Also, it is a way to have a computer-related hobby, that takes me away from the computer. I come back to process the shots, but I had to go walk around the mountainside for 2 hours first.
Oh, and I also like researching and messing with gear of all kinds. You can configure an SLR+lens+lights in the same enless fashions as a MoBo+hard drives+CPU+ Ram, GPU, etc.