Rodenstock / Linos Apo Sironar S 5,6/135 mm NEW, boxed Copal 0, Image circle at 1:infinite=208mm Apo-Sironar-S The Apo-Sironar-S is a lens for universal use which has been modified to provide the highest image reproduction quality. Like the Apo-Sironar-N, its applications are almost unlimited. Its special strengths can be seen when complex, fine structures in the outer part of the image circle have to be reproduced. Its field angle has been increased to 75° and so permit, even more generous shifts. Therefore, the Apo-Sironar-S is also the ideal standard lens for applications which require particularly large parallel shifts to correct the perspective. For instance, the Apo-Sironar-S 150 mm f/5.6 permits up to 10 mm more lateral or vertical shift than the equivalent Apo-Sironar-N lens. As a result of the elimination of the secondary spectrum thanks to the use of ED glass materials with anomalous dispersion (ED = extra low dispersion), no visible color fringing occurs even at edges with extreme contrast. In addition, the light fall-off towards the image corners (vignetting) has been reduced for a more uniform illumination. Thanks to this high optical performance in the edges of the field, the six-element Apo-Sironar-S can be used with f-stop 16 as its working aperture – a special advantage for outdoor shots due to the shorter exposure time this allows.