The Baader Universal Filter Changer System (UFC) is an elegant solution to an ever growing problem that is that new camera-models come to market in ever increasing speed with potentially different specifications. Spacer adaptors between the telescope and the camera don´t always support the correct distance or are subjected to flex due to their length, flimsy design and the possible weight of the (heavy) camera. In addition you may want to change the telescope, or use several different OTAs, but you don't necessarily want to purchase new filters and filter sliders all the time as it becomes expensive, so the Baader-UFC is a (seemingly) simple answer to a complex problem. It is made in the typical Baader-way, trying to connect each and everything in the most elegant and flexure-free manner.
Below is an exploded diagram showing the UFC with its main and core components.
The Universal Filter Changer (UFC) System
The Baader UFC can be thought of in 3 separate parts:
The filter chamber - called the UFC-Base - is the core part of the system.
At present the chamber can accept three different kinds of filter sliders for 2"/ for 50 mm round and for 50x50 mm filter sizes. The filter sliders are kept in place by means of an adjustable magnet, to adjust the retaining force and to assure exact re-positioning of the filter for repeatable usage of flats. A brass-pin mounted onto the far side of the filter-slider. This pin is sticking out at the opposite side of the filter chamber. The pin enables an easy eject of the filter slider without pulling on the filter slider, to not endanger the precise telescope position during exchange of filter sliders.
The camera-side of the UFC-Base (the filter-chamber) remains open towards the camera - until the matching camera-adapter gets mounted directly onto the UFC-Base. The purpose of this is to have the filters mounted with minimum distance to the image sensor, avoiding additional vignetting.
The telescope-side of the UFC-base carries a receptor with 6 clamp screws in 60° spacings, to mount all the Baader-proprietory S 70-dovetail-adapters and spacers. A number of rigid UFC-S 70 spacer tubes is available in 5/15/40 mm length , as well as an ultra-stable S 70 VARI-LOCK spacer, engraved with Millimeter scale and being seamlessly adjustable from 15 to 20 mm. These four spacers will allow precise adaption with almost any backfocus situation, for both - back and prime focus - instrument configurations. Please accept the six tiny set screws, they are dearly necessary at times, when correct spacing becomes difficult. Each joint must be able to rotate, while requiring only a minimum of optical length.
Another set of telescope-adapters, with the male S70 dovetail facing the camera-side, completes the assortment, enabling the user to mount the UFC-assy onto almost any telescope firmly and flexure free. For the RASA-adaptation we even mill this RASA/S70 adapter plate from stainless steel, in order to provide the necessary stiffness while retaining the extremely thin flange tolerances required for the RASA-design.
For any telescope, for any camera - just replace the corresponding adapters on either side of the filter chamber when you change telescope or camera and want to keep on using your trusted set of filters.
As added benefit any camera lens can be used with the UFC. In this case, the UFC-Base will be fastened in front of the camera-lens with adding both the S70/SP54 adapter #2459134 and the retaining flange #2459121, as well as one of the many step-rings of the Hyperion-ring-system (#2958028 - 2958082).
Note : filters ought to be mounted in reverse order when using the UFC-filter changer in front of camera lenses.