Fresnel Lens Spotlight
Fresnel-lensed spotlights are usually lighter and smaller than ERSes. Fresnels have variable beam widths. Moving the lamp closer to the lens makes the field wider; moving the lamp away from the lens makes the field smaller. Their widest beams are wider than the beams from all but the widest of ERSes. The light from a Fresnel is very soft. The beam can be shaped by external “barndoors”, but cannot be cut as sharply as can the beams of ERSes. There are no internal shutters; gobos are not useable with Fresnels.
Some Fresnels have oval beams.
Some Fresnels control the spot/flood setting with a sliding screw on the bottom of the fixture; others use a crank.
Traditional Fresnels use spherical reflectors. Electronic Theatre Controls’ Source 4® PARnel, while designed as a replacement for the Fresnel-lensed spotlight, has a different type of lens and reflector.
Fresnels are useful when you want:
- A soft edge, or
- The ability to vary the field width