A camera module has an image sensor and a lens assembly that includes a lens barrel having a first cylindrical portion that includes an externally threaded portion and a second cylindrical portion that has a larger diameter than the externally threaded portion. A lens moving mechanism includes a movable sleeve having internal threads that receive the externally threaded portion of the lens assembly. The lens moving mechanism is coupled to the image sensor such that the second cylindrical portion of the lens assembly is closest to the image sensor. The camera module is assembled by inserting the lens assembly into the lens moving mechanism from the side closest to the image sensor. An installation tool may engage the second cylindrical portion to rotate the lens assembly and engage the threaded portions. Features may be provided to retain the lens assembly in the lens moving mechanism before joining the threaded portions.