Automatic Measurement of Digital Cameras’ Exposure Time Using Equivalent Sampling

This article presents a novel method to measure the exposure time of digital cameras. The measurement relies on a sequence of images taken by the camera in video mode, using the effect of equivalent sampling. The hardware requirements of the proposed method are low: a signal generator drives an LED source and the blinking LED is recorded by the camera under test. The exposure time is determined from the recorded images and the frequency of the generator. The detailed error analysis of the proposed method is provided, and its performance is validated by real measurements. The measurements indicate that the proposed solution is able to provide estimates with uncertainties in the low microsecond range.