With computer speeds and software accuracy constantly improving, one might wonder why a lighting design firm would bother physical model testing for daylight analysis. Although digital platforms provide a range of robust analysis and design workflows for simulating how daylight interacts with architectural space, no digital simulation can truly account for the full nuance of how daylight interacts with real materials, or how the human eye experiences spaces.

To that end, Lam Partners owns two custom designed and fabricated Heliodons for physical daylight model testing. While much contemporary design work occurs via digital modeling, physical model testing allows designers to test real materials and forms.

Heliodon 3.0

Industrial Design: Associate Principal Justin Brown

A refined version of this model is available for sale. Contact Justin for more info and pricing.


1. Motorized table allows for precise rotation when used in conjunction with video capture. Since the primary advantage of a heliodon is being able to quickly cycle through sunrise to sunset, smooth and repeatable rotation is critical for high quality video output.

2. Wide, stable, field adjustable, and demountable base platform.

3. Constructed of three easy-to-reassemble components using only one size bolt. All necessary tools are stored neatly within the heliodon and easily accessed.

Heliodon 2.0

Also available for purchase. Contact Justing Brown for more information and pricing.

Plywood construction, manual controls. This lightweight model is useful for transporting, but latitude controls are clunky and difficult to adjust. Manual movements require a smooth touch.

Heliodon 1.0 & 1.1

We don’t know where this one is laid to rest, but it served it’s purpose during the time of Bill Lam. These pictures were found in his book Sunlighting as Formgivers for Architecture.


SunScan was a digital interface for reading and recording illuminance levels from a set of illuminance sensors placed inside a model on the heliodon. The custom interface required computer components that are well beyond their useful life. SunScan currently sits in storage.

Sun Dial

Also available for purchase. Contact Justing Brown for more information and pricing.

Improved accuracy of Heliodon 3.0 required a sundial of equal precision. Sundial 2.0 was designed and CNC machined from solid aluminum like the Heliodon (yes, the chips were all recycled!). The new design features an adjustable and lockable latitudinal angle as well as a removable and replaceable gnomon that can be safely stored within the sundial to prevent damage. A polar sundial design was then laser etched onto the front for durability.

Interested in purchasing a heliodon or sun dial? Contact Justin Brown for more information and pricing.