Abstract: For connection in a building between a roof containing a skylight opening and a ceiling spaced from the roof and containing a ceiling opening, a light transmitter is provided. This light transmitter includes a base-frame unit for attachment to the ceiling at the ceiling opening and a light-emitting opening extending through the base-frame unit. The light transmitter also includes: (a) a light duct comprising a tubular member formed from a sheet of flexible material rolled up into a tubular form, and (b) means for attaching the tubular member to the base-frame unit at one end and to the roof at its other end, with the tubular member surrounding a reference line extending between the skylight opening and the light-emitting opening.