A Haze effect is desired to compliment any lighting so that the ray of beams are visible. A haze machine releases a mild haze into the atmosphere so that when a beam of light passes through, you can trace the beam from its source to where it is projected. The haze generated by a hazer is a very fine smoke which does NOT blur images or video and has no smell. A Haze compliments intelligent lighting and lasers as beams become visible and create a perfect lightshow.
A Fog effect on the other hand is recommended for night clubs, halloween parties or any event where there is no photography or videography desired as it blurs out images and video. A fog effect is a cheaper alternative to a haze machine as it too highlights beams of light and adds a smoky effect. A fog machine is NOT recommended for wedding receptions.
Although Haze and Fog are not known to trigger fire alarms, but please consult with your venue to ensure you are allowed to have them brought in for your event.