An optical
system (1000) and luminaire (1100) are provided. The optical
system (1000) includes first (1040) and second (1050) lighting effect assemblies. Each lighting effect
assembly (1040, 1050) includes an effect selector (1041, 1051) and a lighting effect insert (1042, 1052) rotatably coupled thereto. Each effect selector (1041, 1051) positions its lighting effect insert (1042, 1052) in a
light beam. The lighting effect inserts (1042, 1052) include a
prism (104, 204) with a rear surface and a front side having a first plurality of facets (105, 205). The rear surface has a plurality of regions (103, 203) aligned with corresponding facets (105, 205). The regions (103, 203) are color filters. Some lighting effect inserts (1042, 1052) are an effects plate (402, 602) and a
prism (404, 604), where the effects plate (402, 602) has color filter regions (403, 603). The effects plate (402, 602) and the
prism (404, 604) may be separately rotatable at desired speeds and / or directions. Some lighting effect inserts (1042, 1052) are a prism (804, 904) with color filter regions on the facets (806, 906).