Fig. 4.

CRI comparison. A quantitative scale of how well a light source is able to reveal the true color of a material, CRI was developed by the CIE. CRI has positive and negative values, but a value of 100 indicates a perfect match to a D65 color point. D65 is meant to simulate the SPD of daylight at $\sim 6500\mathrm{K}$. CRI has fallen out of favor due to it not being a good indicator of visual assessment. Shown here is the CRI of three dermoscopes (white LED) (top row) to three other light sources including halogen, xenon, and daylight (bottom row). Note that the measurement of actual daylight produced lower CRI values than the halogen source, a known limitation of CRI.