def snapPhoto(camera):
    for i in range(3):
        camera.capture('threaded_photo_' + str(i) + '.jpg')
        # Tried to use video port with no luck
        #camera.capture('threaded_photo_' + str(i) + '.jpg', use_video_port=True)

def runCameraPreview():

    #for i in range(3):
    with picamera.PiCamera() as camera:
        # Get the camera ready
        time.sleep(2)
        print("Starting process")
        # try image capture in a thread
        p1 = Process(target=snapPhoto, args=(camera,))
        p1. start()
        # Do any processing
        print("Waiting")
        p1.join() # Wait for the process to return

runCameraPreview()