code: public void setFovIncrement(double value)
      {
          if (value < 1)
          {
              String message = Logging.getMessage("generic.ArgumentOutOfRange", value);
              Logging.logger().severe(message);
              throw new IllegalArgumentException(message);
          }
          this.fovStep = value;
      }
docs: Set the field of view increment factor. At each iteration the current field of view will be multiplied or divided
  by this value. Must be greater then or equal to one. Default value is 1.05.
  
  @param value the field of view increment factor.
  
  @throws IllegalArgumentException