You will see a lot of pictures with circular light trails behind the Led Poi, just like a comet tail. For a camera to get a good nighttime photo it will use a highly sensitive light setting or a long exposure light setting. The longer the camera exposure the longer any light trail will be. Some people spend a lot of time trying to get the right camera settings and exposure time to create the perfect Best Led Poi picture. The human eye also has a natural light exposure setting with the iris. The darker your spinning area becomes the larger the hole in your eye gets, letting in more light, and then you will begin to see that trail effect. The faster you spin your Poi the longer the trail will appear. However, unlike a camera, your eye has a limitation to how long the LED trail will be.