Stage Precision

Lens Calibration

The main objective of the Lens Calibration Tool is to generate a Lens Profile.
Additional this tool can position/align screens within the correct 3D location/orientation.

Prerequisites

Add the Lens Calibration tool

Once everything has been setup and the camera object is linked properly to the incoming data, the Lens Calibration process can begin.

Go to the camera object, and under the Tools tab, add a new tool under the Calibration folder called Lens Calibration.

Click on the icon to open the Calibration Wizard window.

Start Lens Calibration

Before capturing any images for observations, it is important to ensure that the majority of the markers can be detected properly by the system.

  • If a marker is visible by the system cannot pick it up as a valid marker, there will be no overlay drawn ontop if it. From the capture window, you would just see the marker itself.
  • When a valid marker is picked up by the system, an overlay would be drawn over the marker showing the ID of the marker with a colored background.
  • When a marker is picked up by the system but it does not match the ones that should be in the associated calibration screen, an overlay would be drawn over the marker but with a greyed out background.

Multiple images would need to be captured for the same Zoom and Focus step. Therefore, before you are ready to move to the next zoom/focus step, it is important that the zoom / focus values stay the same during the entire period.

To capture an image click on the icon:

Once an image has been captured, it would appear on the left hand side of the Camera Calibration Wizard window. Repeat the capturing process until the entire image sensor of the camera has been covered.

It is possible to delete and retake some captured images. Select the captured image on the left and press the “del” key, or you can right click on the image and disable it.

Check to make sure that enough images have been captured to get a good distribution of markers across the entire image sensor. This can be seen by scrolling throw the images that have been captured or within the Observation of the Camera Calibration Wizard.

Run Calibration

When a good distribution has been achieved, it is a good idea to run the calibration process now and look at the error margin. To do so, press the icon.

After the calibration is completed, an error margin number would be displayed on each of the captured image. Also, an overall error would be given to a specific zoom/focus step.

If the error is higher than expected, try the following steps:

  • review the already captured images and see if some are extremely high. If so, disable them and run the calibration again.
  • capture more images at different angles / positions.

For more details of how to understand the calibration results, please refer to the Observations view.

Continue with different zoom and/or focus step

  1. For this transition capture, place the camera and/or screen to a place/distance such that the current AND next zoom/focus step can see and detect the markers on the calibration screen.
  2. Check (by zooming in and/or change the focus) if the next observation can properly detect the markers of the screen.
  3. Go back to the current zoom/focus values
  4. make adjustments to the placement of the camera and the screen until both the current and the next zoom/focus step can properly detect the markers.
  5. Lock the camera so it can´t move or rotate and don´t touch the screen at all, once both zoom/focus step can detect the markers.
  6. Click on “Capture Next Step”

  7. Click on “Capture”
  8. Change now to the next zoom/focus values for the next observation
  9. Click on “Capture linked”
  10. Click on “Continue”
  11. Now continue capturing images and repeat all steps until the lens profile is done.