The lens aperture of an f/1.7 lens is a technical figure that describes how much light the lens is capable of transmitting to the image sensor. The f/1.7 value is the so-called aperture number, and the lower the number, the more light will pass through the lens. A lens with an f/1.7 value is therefore highly luminous, allowing you to take better quality and brighter shots in low light conditions, such as at sunset or at night. With more incident light, the camera doesn't need to use high ISO sensitivity, resulting in a clearer image with less digital noise. The low aperture also affects depth of field, which is the range of distances over which objects appear sharp. At f/1.7, the depth of field is shallow, which means the foreground and background can be out of focus while the main subject remains in focus.
