Comparing colour discrimination and proofreading performance under compact fluorescent and halogen lamp lighting

Abstract

Legislation in many countries has banned inefficient household lighting. Consequently, classic incandescent lamps have to be replaced by more efficient alternatives such as halogen and compact fluorescent lamps (CFL). Alternatives differ in their spectral power distributions, implying colour-rendering differences. Participants performed a colour discrimination task – the Farnsworth–Munsell 100 Hue Test – and a proofreading task under CFL or halogen lighting of comparable correlated colour temperatures at low (70 lx) or high (800 lx) illuminance. Illuminance positively affected colour discrimination and proofreading performance, whereas the light source was only relevant for colour discrimination. Discrimination was impaired with CFL lighting. There were no differences between light sources in terms of self-reported physical discomfort and mood state, but the majority of the participants correctly judged halogen lighting to be more appropriate for discriminating colours. The findings hint at the colour-rendering deficiencies associated with energy-efficient CFLs.

Practitioner Summary: In order to compare performance under energy-efficient alternatives of classic incandescent lighting, colour discrimination and proofreading performance was compared under CFL and halogen lighting. Colour discrimination was impaired under CFLs, which hints at the practical drawbacks associated with the reduced colour-rendering properties of energy-efficient CFLs.

Keywords:

• compact fluorescent lamp
• halogen lamp
• colour discrimination
• proofreading
• colour-rendering index

Acknowledgements

The authors would like to thank Eva-Louisa Lamerz and Inga Lewald for their assistance with data collection.

Notes

1. While improved incandescent halogen lamps with xenon gas filling fulfil class C of the energy label and will be marketed only until 2016, improved incandescent halogen lamps with infrared coating conform with class B of the energy label and can be marketed beyond 2016. For details about the phase-out process in Europe and for numerical comparisons of energy efficiency between lamp types, see the FAQ at the official information website of the European Commission's Directorate-General for Energy (2009), http://ec.europa.eu/energy/lumen/index_en.htm.

2. Depending on the types and concentrations of phosphors and activator additives included in a lamp, CFLs achieve very different CRIs that can also be above or below the range of 80–89.

3. There are no equivalent standards for household lighting. Given that there is a considerable overlap between typical office work and work accomplished under household lighting (e.g., paperwork at the writing desk at home), a reference to an indoor work place norm seemed adequate.

4. Counterbalancing order in a within-participants design – as done by Royer, Houser, and Wilkerson (2012) by using a Latin square design – is an appropriate means to control for simple order effects (e.g., participants being generally better in the second condition due to training), but it cannot exclude interaction effects between the light source and the order variable.

5. Tray B was associated with the largest partial error score of all four trays (see Figure 3).