A method of testing a vehicular camera for a vehicular vision system includes providing a vehicular camera suitable for use on a vehicle, with the vehicular camera having a field of view. A collimator is provided that includes an optic and a target. The collimator is positioned in the field of view of the vehicular camera such that the camera images light that reflects off the target and passes through the optic. The target is angled or stepped relative to an image plane of the vehicular camera. Image data is captured with the vehicular camera, with the captured image data being representative of the angled or stepped target. The captured image data is processed, via an image processor, and a defocus of the vehicular camera is estimated based on processing by the processor of the captured image data of the angled or stepped target.