Using smartphone cameras and ambient light sensors in distance learning: the attenuation law as experimental determination of gamma correction

Abstract

In times of the explosion of distance learning, because of emergency due to the pandemic, smartphone sensors and cameras are extremely valuable for teachers as they allow students to perform significant experimental activities in their own homes. The open-source software Tracker can be used in combination with the smartphone camera to perform measurements not only of mechanics activities, but also of optics. In the latter case, it is not always easy for students to understand how the pixel brightness which can be inferred from the taken photos are related to actual physical light intensity. In this paper we present a simple experiment to verify the exponential decay in the intensity of light going through successive sheets of a material (the Lambert law) with two different methods, i.e. using either the smartphone light sensor or the smartphone camera and Tracker. Besides its theoretical significance, the experiment constitutes a useful tool for calibrating the camera/Tracker combination to use it for different experiments.

First results using a Home-Kit designed in the COSID-20 project: teaching physics laboratory at a distance

“…[27][28][29]: (i) for the wavelength calibration we use a commercial fluorescent lamp (the full procedure is described in Refs. [27][28][29]); (ii) to obtain the measure of corrected "light intensity" (luminance) from RGB values we use the transformation formula needed to revert the gamma correction [32].…”

Investigating the Principle of Relativity and the Principle of Equivalence in Classical Mechanics: Design and Evaluation of a Teaching–Learning Sequence Based on Experiments and Simulations

“…The effectiveness of POE in eliciting and uncovering students' misconceptions, and in provoking meta-reflection on them is, we believe, undisputed [65]. A third element we considered is that the sequence would have been tested at least partly in distance learning, using equipment students have at home, or provided in the form of an experimental kit [66], or even by analysis of a video experiment performed by the teacher. Predict-Observe-Explain, as a guided/structured inquiry strategy [67], may be not as effective in sustaining students' engagement, motivating them to science, or improving critical thinking as more open inquiry learning models [68], but has a quite strong record of educational achievements in terms of conceptual understanding, and appears ideal to be adopted when students perform experiments remotely using home equipment or a kit, since does not require autonomous design of new experimental tests by students.…”

Smartphones as Smart Tools for Science and Engineering Laboratory: A Review

“…Efficiencies of incandescent bulbs and halogen lamps as light sources were compared using a smartphone light sensor as a light meter [87]. Beer-Lambert's law was demonstrated by comparing the illuminance transmitted through the media [88][89][90][91]. The reduction in illuminance of light passing through water could be calibrated to determine the liquid turbidity [86].…”