updated example to include centering and better description

examples/wfs_demonstration_experimental.py

@@ -2,8 +2,14 @@
 WFS demo experiment
 =====================
 This script demonstrates how to perform a wavefront shaping experiment using the openwfs library.
-It assumes that you have a genicam camera and an SLM connected to your computer.
-Please adjust the path to the camera driver and (when needed) the monitor id in the Camera and SLM objects.
+It performs wavefront shaping with a FourierDualReference algorithm, maximizing feedback from a
+single region of interest (ROI) on a camera.
+It assumes that you have a genicam-compatible camera and an SLM connected to the video output of your computer.
+
+Adjustments to make for your specific setup:
+* the path to the camera driver.
+* The code assumes the SLM is connected as a secondary monitor. If not, adjust the monitor_id below.
+* The gray value that corresponds to a 2pi phase shift on the SLM. This is used to set the lookup table of the SLM.
 """
 
 import astropy.units as u
@@ -13,19 +19,30 @@
 from openwfs.algorithms import FourierDualReference
 from openwfs.devices import Camera, SLM
 from openwfs.processors import SingleRoi
+from openwfs.utilities import Transform
+
+# Adjust these parameters to your setup
+# The camera driver file path
+camera_driver_path = R"C:\Program Files\Basler\pylon 7\Runtime\x64\ProducerU3V.cti"
+monitor_id = 2
+# time to stabilize the SLM, in frames
+settle_time = 2
+# we are using a setup with an SLM that produces 2pi phase shift
+# at a gray value of 142. With proper calibration, this is usually 256.
+two_pi_gray_value = 142
+centering = Transform(source_origin=(0, 0), destination_origin=(0.0, 0.15))
+
 
 # This script shows how a wavefront shaping experiment can be performed from Python
-cam = Camera(R"C:\Program Files\Basler\pylon 7\Runtime\x64\ProducerU3V.cti")
+cam = Camera(camera_driver_path)
 cam.exposure_time = 16.666 * u.ms
 roi_detector = SingleRoi(cam, radius=2)
 
 # constructs the actual slm for wavefront shaping, and a monitor window to display the current phase pattern
-slm = SLM(monitor_id=2, duration=2)
-monitor = slm.clone(monitor_id=0, pos=(0, 0), shape=(slm.shape[0] // 4, slm.shape[1] // 4))
+slm = SLM(monitor_id=monitor_id, duration=settle_time, transform=centering)
+monitor = slm.clone(monitor_id=0, pos=(0, 0), shape=(slm.shape[0] // 3, slm.shape[1] // 3))
 
-# we are using a setup with an SLM that produces 2pi phase shift
-# at a gray value of 142
-slm.lookup_table = range(142)
+slm.lookup_table = range(two_pi_gray_value)
 alg = FourierDualReference(feedback=roi_detector, slm=slm, slm_shape=[800, 800], k_radius=7)
 
 result = alg.execute()