Leica Summilux-M 28mm f/1.4 ASPH. Black Anodized

The vignetting that is typical of every optical system is naturally more defined on a wide angle lens, particularly a high speed one like this, than on standard lenses or those with a long focal length. At full aperture in 35mm format it is a maximum, i.e. in the corners of the image, of around 3.4 stops. Stopping down to 5.6 visibly reduces this light falloff – to 1.8 and 0.8 stops respectively. Stopping down further does not bring about any notable reduction as essentially only the natural vignetting remains. Distortion is extremely low for a wide angle lens at a maxi-mum of 1.1%, which is rarely noticeable in practice. A total of ten lens elements are used to achieve this exceptional performance. To correct color defects, seven of these are made of glass types with anomalous color dispersion (partial dispersion), while one has an aspherical surface. To maintain performance in the close-up range, one element towards the rear of the optical system is a “floating element” that moves independently of the rest of the mechanism.