A physical assessment device includes an instrument head, an optical assembly and an adapter interface member. The instrument head includes an illumination assembly including at least one LED and a drive circuit for powering the at least one LED with a pulse width modulation (PWM) current to achieve a variable brightness of the at least one LED. The optical assembly includes a plurality of optical components disposed along an optical axis. The adapter interface member enables an image capture device to be attached to the instrument head and aligned with the optical axis. The image capture device is configured to capture images of medical targets when illuminated by the at least one LED. The drive circuit is coordinated with the image capture device to ensure that the medical targets are at least partially illuminated during the capturing of the images notwithstanding the variable brightness of the at least one LED.