INTERCHANGEABLE LENS OPTICAL SYSTEM FOR A QUASI-EXPERT CAMERA, CAPABLE OF UTILIZING FEATURES FROM A TRIPLET STRUCTURE OF A SPHERE

摘要

PURPOSE: An interchangeable lens optical system for a quasi-export camera is provided to obtain a super wide-angle optical system and improve the brightness by identically arranging lenses.;CONSTITUTION: A first lens(10) forms a convex face on an object side and a concave face on the upper side. A plus refractive power is applied to the first lens. A second lens(20) forms a convex face on an object side and a concave face on the upper side. A minus refraction power is applied to the second lens. A third lens formed a convex aspheric side on an object side and a concave aspheric face on the upper side. A minus refraction power is applied to the third lens. A forth lens(40) forms a convex aspheric side on an object side and a concave aspheric face on the upper side. A plus refractive power is applied to the forth lens.;COPYRIGHT KIPO 2011