Influence of light emitting diode correlated colour temperature in visible spectroscopic observation of RGB samples

Abstract

Colour is considered much important in appearance of object in the eye of observer and is usually affected by the source lighting. LED with high efficiency has gained favour from researchers and more effort is done to discover about application of LED. This paper focused on the measurement of surface reflectance of green, blue and red colour paper series in determining the effect of Correlated Colour Temperature (CCT) of white LED on colour spectra. This study is a preliminary step in understanding the interactions between spectral characteristics of light sources and colours. Three white LEDs with different CCTs of 3500K, 4500K and 5700K are used in this experiment. The surface reflectance measurement is done using Jaz Spectrometer within visible range of 380–780nm. The spectra saved are analysed and plotted into scatter plot graphs using gradient of the graphs. CCT of white LED is found to affect spectroscopic view of colour spectra significantly in spectral gradient and insignificantly in peak wavelength values. Lower CCT of LED would improve observation of red series sample while green samples would have greater responsivity when illuminated using higher CCT LED. Due to the high blue radiation of white LED, the observation of blue colour series has greatly been affected and therefore the result is omitted. Different types of white LED are suggested to be used in observation of blue colour series instead.