20mm 3-Up TIR Narrow Spot (15°) Lens Array Optic - Fusion Optix 20XPA3 Series

Technical Documentation

Notes for Table

• Eff.: This is determined by measuring the ratio of the light collected after the Optic output face (excluding scattered light) and dividing this by all the light collected from the LED alone.
• FWHM: Beam angle is typically expressed as the Full Width in degrees at Half Maximum intensity (FWHM); A measure of the width of a distribution defined as the separation of the data points on either side of the peak which have values equal to 50% of the maximum. For intensity distributions this is the angular range at which the intensity falls to half its maximum value.
• Cd/lm: The SI base unit of luminous intensity which is the power emitted by a light source in a particular direction, weighted by the sensitivity of the human eye.
• TIR (Total Internal Reflection) Optic: When light passes from a high refractive-index medium (such as glass) to a low refractive-index medium (such as air) there is a special angle, known as the critical angle, above which light is 100% reflected. Any light rays that fall within the critical-angle undergo total internal reflection. TIR optics use this principle to produce highly efficient optics with a huge variety of beam shapes.

Important Information

20mm TIR Optics The most common size of TIR optic as these produce a range of beam angles from relatively tight to wide. There are also two reflectors within our 20mm range that take the beam even wider â€" therefore, you can design your fixture around this family of optics and select what beam is required as you build.

Full Documentation