An iris calibration device includes one or more groups of light sources, a microcontroller (MCU), and a display. The MCU connects to a system on chip (SoC) of a digital camera device. The digital camera device includes an iris lens. The MCU receives an “on” command or an “off” command from the SoC. The MCU turns on or turn off a group of light sources according to the “on” command or the “off” command The SoC adjusts the iris lens according to an average luminance of the one or more light sources sensed by a sensor of the digital camera device.