Industry references · Development preview
Optical design
Read lighting documentation with three useful distinctions: how a beam angle is defined, what a distribution diagram leaves out, and how an optic relates to its LED. This educational overview does not establish optical performance, certification or compatibility for TaoGroup products.
Unpublished educational preview. Sources checked 5 October 2026; this is a review date, not a publication date. The references include a terminology definition and manufacturer education, not independent product tests.
Read the beam-angle definition
In the Illuminating Engineering Society definition, beam angle spans the directions where intensity falls to 50% of its maximum, measured in a plane through the nominal beam centreline. A beam without rotational symmetry is generally described in two planes 90 degrees apart. The glossary also notes an older 10% convention in some applications. A number labelled beam angle therefore needs its measurement convention and plane to be understood. Source: Illuminating Engineering Society, beam angle.
Look beyond two curves
Fagerhult explains that light distribution is three-dimensional, while a typical polar diagram displays longitudinal and transverse curves in only two planes. The directions between those curves are described in the lighting data file, such as IES or LDT. Its overview distinguishes direct, indirect and combined direct/indirect output, as well as symmetrical and asymmetrical distributions. These describe different aspects of where light goes; a pair of plotted curves is not the complete directional dataset. Source: Fagerhult, Light distribution.
Consider the LED and optic together
LEDiL describes cone-like lenses whose design relies substantially on total internal reflection, or TIR. Typical rotationally symmetrical designs produce a round distribution; oval designs spread light more widely along one axis. Its guide cautions that lens size and LED size affect optical performance, so a lens-family label alone does not establish an exact beam angle. These are descriptions of the manufacturer's optical families, not evidence that an unspecified LED and lens combination is interchangeable or has a particular performance. Source: LEDiL, Guide to TIR lenses.
Three questions for a technical review
Editorial synthesis from the references above: when comparing optical documentation, ask which beam-angle definition and planes are used, whether the full distribution data is available, and which LED and optic combination was evaluated. This is a document-reading checklist, not an installation procedure or a claim that these data are available for the reviewed TaoGroup records.