I've put together an article on the C-Sonnar 50/1.5 and an attempt of an explanation for focus shift, and it has been published on "Theme". Lesson in History: The Magic of the â€œValue for Moneyâ€ Zeiss C-Sonnar 50mm F1.5 | THEME Theme is an online "Photography Daily", and is a nice complement to discussion forums. Interesting articles and photographic news of the day. this is the second article of mine that has been published. The editor has also placed a link back to Leicaplace at the end of the article.