lib/PHPExif/Exif.php
public function getFocusDistance()
    {
        if (!isset($this->data[self::FOCAL_DISTANCE])) {
            return false;
        }

        return $this->data[self::FOCAL_DISTANCE];
    }
public function getFocusDistance()
    {
        if (!isset($this->data[self::FOCAL_DISTANCE])) {
            return false;
        }

        return $this->data[self::FOCAL_DISTANCE];
    }
Returns the focus distance, if it exists

@return string|boolean