The 2.519 MRAD specification for a 9 mm lens indicates which type of lens?

• A. Wide angle lens
• B. Telephoto lens
• C. Normal lens
• D. Zoom lens

Answer: (A)

Short focal lengths yield a wider field of view, while long focal lengths produce a narrower view. A 9 mm lens is a very short focal length, so it captures a broad area of the scene. That broad view is what defines it as a wide-angle lens. The MRAD figure describes how much of the scene the lens covers at a given distance, so a small focal length like 9 mm (and its associated MRAD value) corresponds to a wide angle. In contrast, a normal lens sits around the standard perspective (about 50 mm on full-frame), a telephoto lens uses longer focal lengths to zoom in on distant subjects, and a zoom lens refers to a lens that varies focal length rather than being fixed. So the 9 mm lens is best described as a wide-angle lens.