UFC Camera-Adapter S52a – Optical height: 2mm

The optical height of 13mm is only the UFC filter base. As soon as you add an additional adapter, such as the S52 camera adapter with an optical height of 2mm, the optical height changes accordingly to 15mm. This height is always without the 0.5mm thick intermediate ring. This is only required if you need particularly precise backfocus requirements and you are missing 0.5mm for perfect backfocus, for example. Otherwise, please always use the adapters without additional intermediate rings.

As specified in the technical data the inner diameter is 47,5mm. There is no thread inside, the thread is just like a baffle against straylight.. There is no need to attach filters in this place because its part of the UFC system and the fitlers are placed in UFC filter holders