A METHOD FOR DETERMINING THE DARK RESPONSE FOR SCIENTIFIC IMAGING WITH SMARTPHONES

The proliferation of smartphone technology has provided an unprecedented opportunity for greater community participation in collaborative scientific observations that were once out of reach due to cost, accessibility, and ease of use. Currently, there have been several applications making use of the various sensors included in a smartphone, particularly the image sensor, which has been used in a wide range of scientific endeavors including air quality and medicine. Like all digital image sensors, the smartphone sensor is subject to noise, particularly that related to dark current. The objective of this article is to present the development and testing of a method to determine the dark response that a smartphone camera may experience under different temperatures representative of the environmental conditions for scientific imaging. This has required the development and testing of a specially developed application. This was tested in the evaluation and analysis of the dark response of a smartphone camera for the range of 8–38°C. The mean of the dark response was relatively unchanged over this range. The method developed in this paper allows the rapid and easy determination of the dark response of smartphone image sensors, enabling this to be readily subtracted from the signal in the development of scientific investigations.