Due to the samll opening of the Exakta bayonet, the construction of very fast Topcor lenses must have been quite difficult. Lenses such as the RE Topcor 1.4/58mm and the RE Topcor 1.7/85mm have large front elements, and their entire construction is quite asymmetric. Asymmetric lenses are much more difficult to correct than symmetric ones, and therefore the RE Topcor 1.4/58mm is not as good as the (more symmetric) RE Topcor 1.8/58mm.

		TOPCON AUTO-TOPCOR RE 58mm 1:1.4                 (7 Linsen / 5 Glieder)