Analyzing Color Difference of Digital Cameras Under Different Color Temperatures

Purpose : Dental clinics had a variety of lighting conditions, which could affect digital photography. Digital Single-Lens Reflex Camera (DSLR) was usually used to take intraoral photos. Recently, there has been a growing trend to use smart-phones with the advancement of technology. The aim of this study was to analyze the differences of photographs taken with digital and smartphone cameras under different color temperature conditions.Materials and Methods : Three types of camera equipment were used: a DSLR (EOS 800D; Canon, Tokyo, Japan) with a macro lens (EF 100mm f/2.8 Macro USM, Tokyo, Japan) and diffuser (Lumilab, Gimpo, Korea) and two types of smart-phones; Galaxy (Samsung, Suwon, Korea) and iPhone (Apple, California, USA) with Smile line MDP (Smile line SA, St-lmier, Switzerland). All photographs were taken 30 times for every 500°K color temperature from 3500°K to 6000°K. Color information was extracted from the central part of the tooth using image editing software (Adobe Photoshop CS4, Adobe, California, USA). ΔE value was calculated by this formula based on CIE L*a*b* color systems. All statistical analyses were performed using SPSS (version 23, SPSS, Chicago, USA), with a significance level of 0.05.Results : In this study, DSLR showed the highest ΔE value followed by iPhone and Galaxy. DSLR showed minimum ΔE value in 4O00°K, iPhone and Galaxy showed in 4500°K. The lowest L* value was DSLR, followed by iPhone and Galaxy. The highest a* value was DSLR, followed by iPhone and Galaxy, except for 4000°K. The lowest b* value was DSLR, followed by Galaxy and iPhone. So DSLR was the darkest, reddest, and bluest of the three equipment.Conclusion : Although there was a significant difference from the actual shade, Galaxy showed the most similar color. Because each device showed different results, it was essential to consider the characteristics of each imaging device.