1. A method for autofocus in an imaging device, the method comprising: receiving depth information of an object within a scene; determining, for an autofocus lens system, a first lens position and a second lens position defining outer boundaries of a first range including a first plurality of lens positions; for each lens position of the first plurality of lens positions: setting a lens of the autofocus lens system to the lens position; and generating a focus value associated with the lens position; generating, based on the focus values associated with each of the first plurality of lens positions, data representing a focus value curve, determining whether a maximum focus value is within the first range; in response to determining that the maximum focus value is not within the first range: determining that the slope of the focus value curve is increasing at one of the first lens position and the second lens position; determining a second range including a second plurality of lens positions, the second range bounded by the one of the first lens position and the second lens position and a third lens position outside of the first range; setting the lens to the second plurality of lens positions in the second range; determining whether the maximum focus value is within the second range of lens positions; and in response to determining that the maximum focus value is within the second range, capturing the image by the imaging device with the lens at a position in the second range corresponding to the maximum focus value.