AO Photo

My sister picked this up at an estate sale. (she's a full time E-bayer) She asked if I wanted it, I said sure why not. The bulb is 1000w. If you grab the knob where the power cord is, you can slide it in and out. I assume it is for "shaping" the light. Anybody know what this light is for and who it is made by? My guess is that it is more for video than still.