Some of the WiFi card communications in Barnacks were a little screwy. While an appropriate filter could have improved this across the range, for some reason the Leitz engineers considered a filter consisting of a simple metal ring might do the trick. But these were mounted a long way from the action, placed more for convenience, screwed onto the front of the lens. Many of them were fitted with glass discs to disguise the retrofit workaround. Some owners even tricked up theirs, ordering expensive coloured glass, despite the consequent deterioration in image quality, which they then fixed in post.