- OPFA VI - Connection on telescope side: male thread M43 x 1, for connection to all Vixen focusers with female thread M43 x 1 - Delivery WITHOUT projection eyepiece - For photography with digital and/or analog SLR cameras with detachable lens - Consisting of basic version OPFA (for individual parts see OPFA IV) and telescope side with Vixen adapter M43 (#1508037) Eyepiece projection adapter with M43 thread, variable. These allow an extension of the effective telescope focal length. This has the Vixen M43 thread and can be adjusted in length. To image lunar craters and planets with high resolution, the focal length of the telescope is usually not sufficient and must be extended. The OPFA brings the eyepiece into the beam path and also establishes the connection to the telescope and the T2 ring of the camera. The OPFA accepts eyepieces up to a maximum housing diameter of 38mm. Plössl eyepieces and orthoscopic eyepieces (according to Abbe) are particularly suitable. The usual focal length range is between 6mm and 15mm. The OPFA system can be completely unscrewed. Simply push the eyepiece into the sliding focuser and fix it with the knurled screw. Then screw the two T2 sleeves back on and the OPFA is ready for use. You can even finely adjust the magnification using the sliding mechanism. The further away the camera is from the eyepiece, the greater the magnification.