LightBench: A Laboratory Testing Procotol for Comparing the Performance of Flashlights and Headlamps

Introduction

Comparing the performance of handheld flashlights and headlamps objectively is challenging because there are so many design attributes that contribute to lighting performance. Not only are we concerned about brightness, efficiency, weight, and battery life (easily measurable attributes), but we also care about ergonomics, aesthetic design, beam quality, and ease of use. These attributes are more difficult to correlate with objective performance measures because different users have different needs.

In a recent survey of Backpacking Light users (November 2024, 1370 respondents), the most important features considered when selecting a light were identified as weight (78%), the presence of a rechargeable battery (57%), and maximum burn time (55%). In addition, brightness at maximum power (42%) and battery life at maximum power (32%) were not insignificant considerations.

Unfortunately, light manufacturers are not required to disclose technical performance details about their products, although some opt-in to standards such as the ANSI (Plato) FL1 standard. In that particular case, the Light Output ANSI standard for measuring lumens is reasonable. However, there is controversy over the usefulness of Beam Distance, Run Time, and Peak Beam Intensity standards in the context of how lights are used in the field by backcountry, tactical, and military users.

In this technical brief, we present a laboratory (bench-scale) method for quantitatively evaluating (and comparing) the performance of lights using an objective, measurable, and normalized metric (the LightBench Index) that considers brightness, how long a battery lasts during a single discharge cycle (a.k.a. runtime), and product weight. In general, the LightBench Index (LBI) is defined as follows:

LBI = brightness × runtime ÷ weight {eq. 1}

where brightness × runtime is an approximation of the total volume of light output by a product during a battery discharge cycle (we refer to this as light volume or LV in this report).

The LightBench Index (LBI) was developed to address the lack of standardized, weight-normalized metrics for evaluating lighting performance in backcountry environments.

Two lighting products are used to illustrate the concepts: the Petzl Actik Core (v1 model, ca. 2019) and the Fenix HM50R (v1 model, ca. 2019). Updated (2024) versions of both lights are also being tested; those results will be released in upcoming test reports that compare several different brands and models.

Table 1. Physical specifications for the Fenix HM50R vs. Petzl Actik Core