Compact lens systems are described that may be used in small form factor cameras. The lens system may include six lens elements with refractive power, and may provide low F-numbers with wide field of view while maintaining or improving imaging quality and package size when compared to other compact lens systems. The lens system may, for example, provide a focal ratio of 2.1 or less (e.g., 1.8), with full field of view within a range of 70 to 90 degrees (e.g., 81 degrees). The lens system may conform to a criterion for compactness TTL/ImageH