I bought recently an expensive Carl Zeiss lens for my Zeiss Ikon rangefinder camera and wanted to protect the lens. So UV filter on it. Just what? The photo dealer said, with a cheap filter would not make sense as a high-quality lens. Other photographers say cheaper do it well, light and quality loss would not be noticeable or measurable. Because I wanted to be on the safe side, I thought to myself, Zeiss filter on Zeiss lens (yes it is, especially for the Zeiss lenses made) and have 50 EUR invested. Ultimately, for the good feeling and because I trust the brand. If someone has had different experiences, I would be quite interested in the.