I first thought of doing this when I noticed that when I flung rubber bands into the trail of a laser, they lit up and made a red line in the air. I played around with the camera, took photos of this and then thought of using the laser directly to draw.
Not sure if this is up anywhere, didn't see it. If it is, I hope this will add some more information or help anyone with anything. It's a very simple process I thought I'd tell anyone who didn't know.
Step 1: Materials
First of all, you will need a laser. Whatever colour you want, as long as you can draw with it. Mine's red.
Next you'll need a decent camera, one of those big fat ones. It must have adjustable shutter settings and maybe ISO settings if you want.
You will need a tripod, or something to stabilize the camera, as any shaking will blur the image.
Oh, and a dark room is desirable.
Step 2: Preparation & Method
First of all, get into a dark room, attach the camera to the tripod and then set it so it's facing whatever you want. Make sure it's not going to move, even on the tripod.
I find that an ISO of 100 - 200 works well, as to keep the backdrop dark and the laser still bright for the best contrasting photos. I set the shutter speed to 4 seconds, partly because it's good for most drawings, and it's the maximum on my camera.
To those unfamiliar with camera stuff, a 4 second shutter speed will leave the shutter open for 4 seconds and everything the camera sees in that time enters the photo, so you have 4 seconds to make a good drawing.
Try and position the laser so when you're drawing, you're pretty much parallel and on the same axis as the camera to reduce the laser making shadows from being shone on an angle, if you know what I mean. Make sure you know what area will be in the photo, as it sucks when you draw it all perfect and half of it is left out.
Finally, click the button, write or draw what you want on whatever you want and then marvel at the awesomeness you have created. This process is great for tagging stuff and the pictures make great desktop wallpapers.
Step 3: Product