135mm f/5.6 Apo-Sironar-S A compact&#44; extremely sharp slightly wide lens for the 4x5 format. Increased coverage (to 75) for the classic 6-element&#44; 4-group optical design. Use of extra-low dispersion (ED) glass allows for no visible color fringing&#44; even at edges. Brighter ideal working aperture range of f/11-22 allows shorter exposures and sharper outdoor images. Weighs just 8.5 oz (240g) and has small 48mm rear outer barrel to allow use of small camera lensboards.