The dust and moisture-resistant Sony Ultra Wide Angle Converter for E-Mount FE 28mm f/2 Wide Angle Lens provides a 21mm focal length. This easy to attach lens accessory is composed of 4 lens elements in 4 groups and has a built-in petal-type lens hood is also capable of EXIF Data Generation for a more efficient data management. Product Features in Detail New expression with a wider view A 21 mm focal length makes it possible to capture sweeping views with impressive perspective indoors or out, particularly when shooting in the full-frame format. Wide 21 mm is an advantage indoors or outA 21 mm focal length not only allows you to capture wider scenes, whether you're shooting scenery outdoors or a group of people indoors, for example, but it is also capable of producing strong perspective that can emphasize the size of objects in the foreground as well as the distance between foreground and background objects. Automatic EXIF data generation A sensor system detects when the converter is mounted so that appropriate EXIF lens data is generated and recorded by the camera. That makes data management easier when you sort or process your images later. Smooth visual match with the FE 28 mm F2 Not only are the Ultra-Wide Converter optics designed specifically for the FE 28 mm F2, but the visual appearance is too. The converter blends smoothly with the lens when mounted, giving the appearance of a single integrated unit. High reliability in harsh conditions Like the lens it mounts to, the Ultra-Wide Converter has been designed to resist the intrusion of dust and moisture so it can be used with confidence even in challenging outdoor conditions.