Creating a Camera Sensor in Geometric Mode

This page shows how to create a Camera Sensor using the Geometric mode. The Geometric mode is a simplified mode that allows you to define a camera sensor without having to set every parameter of the sensor.

Note: The geometric camera sensor can only be used in inverse simulation without sources or other sensors. In Geometric mode, all parameters relative to spectrum or spectral data are disabled.

To create a Camera Sensor using the Geometric Mode:

  1. From the Light Simulation tab, click System > Camera .
  2. From the Mode drop-down list, select Geometric to enable the simplified definition.
  3. Define the Axis System of the camera sensor in the 3D view by clicking to select an origin, X to select a line and Y to select a line or click and select a coordinate system to autofill the Axis System.
    Important: Make sure the sensor is not tangent to a geometry.
    Note: Depending on which camera model is described in the .OPTDistortion input file, the origin of the sensor is different.
    • If the .OPTDistortion file is based on the Basic Distortion Curve model (v1 version), the origin corresponds to the Entrance Pupil Point (EPP) of the camera.
    • If the .OPTDistortion file is based on the Speos Lens System model (v2 version), the origin corresponds to the center of the sensor.
    Note: If you define manually one axis only, the other axis is automatically (and randomly) calculated by Speos in the 3D view. However, the other axis in the Definition panel may not correspond to the axis in the 3D view. Please refer to the axis in the 3D view.

    If you need to adjust the axes orientation, use Reverse direction on one or both axes.

  4. In the Optics section, define all the parameters of the camera:
    Note: Only the *.OPTDistortion V1 model is compatible with the geometric mode.
    Note: Horizontal/vertical fields of view set to 0 are not supported and may generate incorrect result. If the values are set to 0, refresh the Camera sensor feature.
    1. In Focal length, adjust the distance between the center of the optical system and the sensor (in mm).
    2. In Imager distance, you can adjust the distance between the aperture and the sensor.
      Note: Imager distance does not affect the results. Changing it is only used for visualization purposes and does not represent the real sensor.
    3. In F-number, type the size of the aperture of the camera's front lens.
      Note: The smaller the number, the larger the aperture.

      The irradiance is calculated from the radiance by using an acceptance cone for the light (the cone base is the pupil).

      More details about the F-number can be found here.

    4. In Distortion, click Browse to load an .OPTDistortion file V1.
      The *.OPTDistortion file is a file that contains information on the camera and is used to introduce/replicate the behavior of the camera lens.
      A preview of the camera sensor system appears in the 3D view.
  5. In the Sensor section, define the size and resolution of the sensor:
    1. Define the number of horizontal and vertical pixels corresponding to the camera resolution.
      Note: Speos supports a maximum resolution of 23170 * 23170 pixels.
    2. Define the sensor's height and width.
  6. If you want to adjust the preview of the sensor, click Optional or advanced settings :
    1. Activate or deactivate the preview of certain parts of the system by setting them to True/False.
    2. Adjust the Visualization radius.
The Camera Sensor is created and visible in Speos tree and in the 3D view.