The 35mm Summicron is the most widely used lens of any Leica system. The slightly wide perspective lends itself well to most subject matter. The Leica Summicron is legendary among lenses, an the R version of this lens is no exception. There were basically two versions of this lens. The early version was substantially heavier and incorporated two extra elements when compared to the later/current version of this lens. The early version also had a wider focusing ring than the second version allowing for a better and more secure grip. It can be argued as to which one is better, but let me assure you that either one of these lenses will perform way beyond the limitations of any other 35mm lens. Once again, using the lens wide open at F2 yields perfectly sharp and contrasty pictures. Apertures are only used for creative control, not to make the image quality better as is the case with all other manufacturers lenses. The Leica R system is todays best bargain, and the 35mm Summicron is a good place to start along with a nice Leicaflex SL. Soon the prices will go up on Leica SLR equipment as people come to realize how fantastic this system really is.