The S2 finder spoils you for using a 50. How much? I really like the Zeiss-Opton 50/1.5 that came with my Contax IIIa. I re-shimmed the S2 to properly focus with it. The Contax got a Helios-103. Later, Oscar traded me a 2nd Zeiss-Opton 50/1.5. I love the Contax IIIa, smooth, but The S2 finder spoils you.