I was trying to clean the dust from my sensor. Afterwards, just for the heck of it, I aimed the Sigma 55-200 at a lamp on my desk. The white balance was wrong. And the dust on the lamp was startling when I saw it on the picture. But I still thought the image was rather interesting so I posted it. The lighting is just a 60 watt bulb, the background is actually navajo white. Maybe I'll do it again after I dust it!