An electronic device comprises a camera and a retaining member. The camera includes an objective portion configured to collect light from a subject, a sensor portion reversibly separable from the objective portion, an alignment-sensing system configured to sense a state of alignment between the objective portion and the sensor portion, an actuator configured to move the objective or sensor portion, and a computer configured to control the actuator responsive to output of the alignment-sensing system, so as to bring the objective and sensor portions into alignment. The retaining member is configured to couple the objective portion to the sensor portion when the objective and sensor portions are aligned and when the objective portion is separated from the sensor portion.