Lens information and Focus position

Get a table for converting CrDeviceProperty_FollowFocusPositionSetting and CrDeviceProperty_FollowFocusPositionCurrentValue to Focus position (meters/feet).

Valid only when compatible lens is attached.

Valid only in movie mode.

- See to How to use Focus Position Setting in Tips / Trouble shooting.

The following are available when CrDeviceProperty_LensInformationEnableStatus is set to Enable.

Example:

std::vector<SCRSDK::CrLensInformation*> m_lensInfo;

  // Call the request
  CrError err = SCRSDK::RequestLensInformation(handle);


// When the OnWarning callback notifies you of success:
  CrInt32u numOfList= 0;
  SCRSDK::CrLensInformation* list = nullptr;
  CrError err = SCRSDK::GetLensInformation(
    handle,
    &list,
    &numOfList);
  if (CR_SUCCEEDED(err) && 0 < numOfList) {
    for (int i = 0; i < numOfList; ++i) {
      auto item = new SCRSDK::CrLensInformation();
      item->normalizedValue = list[i].normalizedValue;
      item->focusPosition = list[i].focusPosition;
      m_lensInfo.push_back(item);
    }
    // release of list pointer
    SCRSDK:: ReleaseLensInformation (handle, list);
  }

The information retrieved by GetLensInformation() can be used to know the Focus position (meter/feet).

Example:

// Example of a case where CrDeviceProperty_FollowFocusPositionCurrentValue is 0x00001234
CrInt32u followVal = 0x00001234;

// If Focal distance unit is “Feet”
CrInt32u unitFeet = SCRSDK::CrLensInformationType_Feet;

for (int i=0; i < (m_lensInfo.size() - 1); ++i) {
  if (m_lensInfo[i]->type != unitFeet) continue;
  if ((m_lensInfo[i + 1]->normalizedValue <= followVal) &&
    (followVal <= m_lensInfo[i]->normalizedValue)) {
    printf("Follow Focus Position between %d and %d\n",
            m_lensInfo[i]->focusPosition, m_lensInfo[i + 1]->focusPosition);
    break;
  }
}