what you are trying to take a picture of. If you have the ability to set the focus length manually then I would suggest doing this. Photo. Shutter speed The longer the exposure time the longer the flame trail. Time how long it takes the poi/staff swinger to do 10 rotations (eg 10 seconds). Divide this amount by ten.This will give the exposure time for one full revolution of the POI (eg 1 second). If you want a short flame trail, about half a rotation, then set the exposure time to half that value (0.5 second). Photo. Flash at end of long exposure Some more expensive cameras have the ability to do a long exposure and then flash at the end before closing the shutter. Check your camera manual to learn about this function. What does this achieve? Looking to the right at Jeremy's photo you will see that the long exposure time shows one full rotation of the flame and the flash catches Jeremy's body at the end producing a clear image of him standing on some sand. Make sure you have the flash the optimal distance away from your performer. Some flashes do not work well over longer distances. Again see your manual. There are also multi flash functions within a single exposure. Lots of fun effects can be achieved with these functions.