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

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

        return $this->data[self::APERTURE];
    }
Returns the Aperture F-number

@return string|boolean