Baader UFC Universal Filter Changer System

During the transition from OSC to MONO astrophotography, I had to choose a filter system. I decided on the Baader UFC.

Why I chose a drawer system instead of a filter wheel is explained in the main article.

MONO Astrophotography – here I come – The Main Article
ToupTek SkyEye62AM Hardware
Baader UFC Universal Filter Changer System
Gerd Neumann CTU XT M54
ToupTek SkyEye62AM Software
Pegasus Astro Indigo OAG
Baader LRGB CMOS Filter 50.4mm

The choice quickly fell on the Baader UFC filter drawer system. The reasons include both subjective impressions and personal preferences, as well as objective criteria.

I currently use two telescopes, both of which do not come with the standard “off-the-shelf” thread sizes. My VC200L features the Vixen-typical M60 threads, while my Baader 95/580 CaF2 uses the Zeiss M68 thread.

This circumstance alone, combined with the desire to use both telescopes with the same camera, posed a challenge for which I would have loved to call on Doctor Snuggles for help – because simply screwing the components together is far from sufficient.

Link to the Baader UFC Page

Initial Situation

Framework Conditions for the New Overall Solution (Mandatory or Optional):

High quality
Experienced manufacturer
Telescope-side threads: M68, M60, M54
Camera-side connections: M54, optionally EOS mirrorless
Compatibility with 50.4mm round filters
Long-term availability of components

To adapt the mono camera to my Baader refractor, I need to maintain a backfocus of 76.11mm behind the flattener. With my Vixen VC200L, at its native focal length of 1800mm, there are no significant constraints to consider. This allowed me to focus on the configuration for the Baader refractor during the design decisions – so that’s exactly what I did.

The setup of my overall system is fundamentally as follows:

The telescope and OAG are already in place and therefore fixed. Adapting from M68 or M60 to the OAG (M54) is no longer my concern. The focus is on bridging the M54 from the OAG to the M54 of the mono camera. This simplifies the challenge – though it wasn’t necessarily required.

The Baader UFC system provides all the modularity I could have hoped for.

To integrate the UFC system into my optical setups, I need exactly four components.

The Filter Base
Adapter for the Camera Side
Adapter for the Telescope Side
Filter Drawer

UFC Base

There is exactly one type of filter chamber—the UFC Base.

The UFC Base has an optical length of 13mm. The three other components integrate with the UFC Base to form the desired filter system.

Camera Adapter

On the camera side, there are a variety of adapters. Many of them have an optical length of 2mm. This includes the M54 adapter I need to attach the M54 tilter in front of my camera. The camera adapter is securely fastened to the UFC filter chamber with 8 screws provided.

Telescope Adapter

On the telescope side, the UFC base does not have a screw fastening but features a dovetail system held in place by 6 screws, which adds particular significance to me. More on that later.

On the telescope side of the UFC filter chamber, I have an OAG with an M54 thread. Therefore, I use the SP54 adapter with a 1mm optical length.

Filter Drawer

As described in the main article, I chose unmounted 50.4mm filters. For this size, there are also the appropriate filter sliders. These sliders come in 3 sizes and 3 inserts, so there are net sliders available from 1.25” to 50mmx50mm in 6 different sizes.

Further Thoughts

All in all, the complete UFC filter system in my setup achieves a sleek 16mm optical length, including both adapters. It’s ideally suited for my needs and performs excellently.

Baader provides a wide selection of adapters on both sides of the UFC base. Additionally, there are extension options for the system, which haven’t been necessary for me so far.

A critical aspect for me was the telescope-side adapter’s dovetail attachment to the UFC base. This setup allows me to easily switch the camera and filter system between telescopes.

In the end, I will need an OAG on the VC200L, but I also have the flexibility to switch to a guide scope if required.

The dovetail mechanism is not a quick-release unit. Given that I will likely change telescopes 2-3 times a year, the 2mm SP54 adapter should last for several years.

The assembly of the entire system was straightforward with no complications. I believe Doctor Snuggles would be impressed with the outcome. I’m eagerly anticipating the first light!