A friend and fellow turner tipped me off that he had abandoned his laser hollowing system for one that uses a camera and a monitor. I did a bit of polking around on the web and found a nice video by Michael Gibson ("Hollowing with a Monitor") on Youtube. So, I took the plunge and bought an automobile backup camera with monitor ($60) and a 12V power supply ($20). I replaced the laser from my Monster Articulated Hollowing arm with the little backup camera and mounted the monitor directly on my Carter stabilizer. The idea is to trace the shape of the cutter directly on the screen with Dry Erase marking pens so that when the cutter disappears into the bowl interior the exact location of the cutter is still shown by the tracing. In the pictures I've included, the red arc indicates the desired wall thickness so when the arc gets to the edge of the bowl, you're there. I used this in hollowing my current bowl and it works very well--much better and more precise than the laser.