Spectral surface damage, TU Berlin (Aydinli)
Full-spectrum LED
XPECTRUM, XAL’s new daylight-like full-spectrum LEDs
achieve excellent Ra and Re > (greater / equal to) 98 (or
TM-30 rf), thus offering improved visual comfort. Thanks
to this high colour fidelity, the human eye perceives
products in the shop more easily and authentically. In
addition, the strong, natural colours have an activating
and emotional effect on the customers. The shopping
experience has never been more appealing.
Top flexibility and light quality
Complementing the XPECTRUM LEDs, the special LED
modules for fashion and food have proven their worth in
staging goods in a sales-boosting manner. The flexibility
that retail operators have to ideally match the light colour
to the application is a major advantage. The custom colours
offer product presentations of significantly higher quality
than the 3000 K light colour that has been used across the
board to date.
Thanks to the targeted use of the special LED modules, we
can now optimise the sales areas according to the merchan-
dising requirements. Different collections require different
light qualities. For example, the BRILLIANT light colour can
make the smallest nuances of white surfaces visible in clas-
sic men’s departments or in bridal fashion. Product-specific
lighting qualities encourage purchasing decisions and raise
the store’s quality to a new level.
Colour fading due to light
Since the introduction of LED light sources, it has been
assumed that the risk of colour fading has largely been
neutralised thanks to the elimination of UV wavelengths.
Nevertheless, extended periods of illumination at high
illuminance levels can visibly damage the colour.
Generally, cool white light colours have a higher damage
potential than warm white light colours. LED lamps’ poorer
colour rendering index indicates stronger potential for
damage than a high colour rendering index because at a
high value the intensity of red wavelengths is also signifi-
cantly higher.
Increase illumination distance:
Since the intensity of light decreases with the square of
the distance, e.g., a doubling of the illumination distance
has only 1/4 and a tripling of the distance only 1/9 of the
original damage potential (photometric law of distance).
Use lamps with low intensities of blue wavelengths:
• Use warm white light colours <
3000 K with a high
colour rendering index Ra > 90
• Do not use LEDs with a violet GaN chip such as PHILIPS
Crisp White, Brilliant White, or SORAA.
Dimming:
• Operate the luminaires at, e.g., only half the current
• Use wide beam optics
Limit lighting duration:
Textiles that are illuminated at > 3000 lx should be
changed monthly.
Measures to prevent colour fading
The image shows there are only a few harmful blue
wavelengths in this LED spectrum. Colour temperature
≤ 3000 K and CRI ≥ 95 (such as SASSO 60/100) is recom-
mended for sensitive surfaces.
Light quality for fashion
Relative sensitivity s (λ)dm, rel
Textiles
300 nm
400 nm
500 nm
600 nm
700 nm
780 nm
λ
1
0,9
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
Relative Empfindlichkeit s (λ)dm,rel
Spektrale Oberflächenschädigung nach TU Berlin (Aydinli)
3000 K CRI 95
Textilien
300 nm
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1
400 nm
500 nm
600 nm
700 nm
780 nm
3000 K CRI 95
Know-how
380
780
480
680
580
380
1
780
480
Relative Intensität
680
580
Lamp data
Spectrum of sunlight
XPECTRUM LED
relative idensity
XPECTRUM
4000 K BBC (reference)
380 nm
480 nm
580 nm
680 nm
780 nm
380
780
480
680
580
380
1
780
480
Relative Intensität
680
580
Lamp data
Spectrum of sunlight
Commercially available LED 4000 K
relative idensity
4000 K CRI ≥ 80
4000 K BBC (reference)
380 nm
480 nm
580 nm
680 nm
780 nm
74
