Are you looking to develop a quick back-of-the-envelope Solatube Product design layout prior to performing a rigorous Daylighting Design and Analysis design evaluation? Over two decades ago, Solatube International develop advanced optical systems to pioneer and perfect the concept of the “Daylight Fixture”, meaning that while lumen output will vary depending upon the exterior, roof-top available daylight resource, the Solatube Daylighting Systems are optically-engineered to deliver daylight with a remarkably-consistent distribution pattern of daylight throughout the day and throughout the year. This unique attribute of Solatube Daylight Systems allows them to be applied using the same basic spacing criteria that lighting designers and engineers have used to achieve acceptable task-plane illuminance uniformity for electric lighting solutions for over 100 years.