Hello! This is my first post... I've recently found the beautiful wetplate photography and decided to go and buy myself the equipment I need. On the internet I found a Rodenstock Bistigman 18x24 lens. The problem I have, is that in the description of the lens it says: "The shutter works, but runs slowly." What does it mean? Is the lens unusuable? Is the Rodenstock Bistigmat 18x24 appropriate for beginners, easy to handle and produces sharp pictures? Best Regards to you all!