1. A light future for sensory methodology: development of sensory methods for lighting
M. Boork, J. Nordén, K. Wendin
The project aims to apply sensory methods to lighting to complement physical measurements. The results will promote more desirable lit environments and increased knowhow with regards to user perception and comfort. The long-term goal is to reinforce both development and use of attractive and energy efficient lighting.
4. Conclusions The results show that:
It is possible to make analytical assessments of lighting
Characteristic properties of lighting products can be identified
Assessments in a real context produce the same results as laboratory assessments, but are less significant
SP Technical Research Institute of Sweden
1. Background Current standards for lit environments are solely based on technical requirements, e.g. brightness, uniformity and luminance. Including experience-related requirements would most likely yield better lighting comfort. However, lack of knowledge on how to describe perceived lighting parameters hampers users and building owners in specifying desired lit environments and for lighting manufacturers to develop products for new markets. The aim of this research project is to apply and develop sensory methods for lightning. The future vision is to enable more desirable lit environments and increased knowhow with regards to user perception and comfort.
Attributes
Definitions
Glare
Degree of glare - eye irritation. Look from bottom to top (i.e. not directly on the light source) and look at the text that is posted on the wall in the joint between the wall and ceiling.
Flicker
Degree of flicker (look at the text that is posted on the wall at the joint between the wall and ceiling)
Yellowness of the light source
Degree of yellowness (look at the text that is posted on the wall at the joint between the wall and ceiling)
Heat from the light source
Degree of heat on the back of the hand (hold your hand at the level of the ceiling for 5 sec)
Unevenness
Light unevenness on the entire rear wall.
A little = completely equal distribution, A lot = shady and uneven
Sharpness of shadow at the frame
The sharpness of the dominant shadow from the left side of the frame on the table (2-3 cm from the front edge of the frame) at the bottom corner in level with the rear side of the frame.
Sharpness of the shadow of the frame at the back edge
The sharpness and clarity of the dominant shadow from the top of the frame on the table, near the wall where the table meets the wall.
Multiple shadows
Degree of multiple shadows near the wall where the table meets the wall.
A lot = several well- defined shadows
Reflection from the table
Degree of reflection in the table top in front of the frame with glass (near the frame and when you vary your body position)
Reflection from magazine
The panelists were instructed to turn to a certain page in the magazine. Roll the magazine to half side, lift the magazine and look at the picture in the upper edge. Assess the strength / degree of reflection in the image. Assess the maximum reflection.
Readability of magazine
The panelists were instructed to turn to a certain page in the magazine and read any part of the text (the body of the ad). Leave the magazine lying on the table. Assess contrast as a measure of readability.
Depth of colour: Yellow
Look at the color chart in the frame without glass. Assess color match to the reference color in the preparation room.
Depth of colour: Blue
Depth of colour: Green
Depth of colour: Red
2. Material and methods Analytical assessment of lighting has been carried out in a multi-sensory laboratory at SP Technical Research Institute at three different occasions. Preliminary panel selection criteria were identified and eight persons were trained to carry out assessments of downlight fixtures. The training resulted in attributes and definitions given in Table 2. Special emphasis has been given to improvements of the training procedure.
3. Results The panelists were able to distinguish between attributes and samples. The four samples were mainly separated by the attributes Multiple shadows, Uneven, Glare and Yellowness, see spider plot below.
5. Further information Methodology, lessons learnt and results from the initial assessments can be found in the report “Development of methods for objective assessment of lighting – a pilot study” (SP Report 2015:26), available for download from
Acknowledgements The research was financially supported by the Swedish Energy Agency. A special thank to Carolina Hiller, Nata Amiryarahmadi, Maria Nilsson Tengelin, Dag Glebe, Per Olof Hedekvist and Niklas Rosholm for sharing their insights during the pilot study.
Product number
Type of product
CCT
Reflector 1
Downlight
3000K
Facetted specular 2
4000K 3
White 4
Contact
Magdalena Boork,
Karin Wendin,