fhotoace
The link is broken, but I will assume what you are asking has to do with what is called light graffiti. You need a tripod and remote shutter release. At night, set your cameras shutter speed to bulb and manually focus the lens to the point where you will be drawing your art in the air with a light pen, LED or other light emitting device. Standing in the pre-focused area, use the remote shutter release to open and then hold open the shutter until you have finished drawing your art. Release the shutter. Review the results on the cameras LCD and then adjust the lens aperture to assure that the image is neither over or underexposed. Now you have it and can do this anytime you wish