The 10" F10 Barndoors for the LS 600d Fresnel Attachment from Aputure offer a means to control the 15 to 45° beam spread range of the Fresnel. Simply swing one or more leaves into the beam path to light areas you want and to keep light from areas you don't want illuminated. The 8-leaf design gives even greater control than 4-leaf versions and provides clean cuts of light.