The Fisheye-Elmarit-R 16mm f/2.8 is of the full frame type (covering the full 24x36mm). It has eleven elements in eight groups. The lens covers 180°. Straight lines passing through the lens axis (like the horizon) are reproduced straight while the sides of the images exhibit barrel distortion. It is an ideal lens for landscapes, city and experimental architectural photography. This is clearly a specialty lens for the serious and creative amateur photographer. It takes a while to master in order to produce interesting and lasting images. With care for subject and camera position it is even possible to take pictures without revealing that they were taken with a Fisheye.The lens has a large depth of field. As with other super wide-angle lenses, emphasis is being put on the object in the foreground. One has to be careful no to include feet while taking pictures! Also, since its angle is 180°, light metering may require special attention (bright skies, strong light sources like the sun). The Fisheye-Elmarit-R 16mm f/2.8 displays good contrast and definition wide-open, which will be enhanced by stopping down to f/5.6. Vignetting is non-existent.