Baader Universal Filter Changer (UFC): Part 1 - a simple overview

The Baader Universal Filter Changer (or UFC for short) is a very versatile simple system for using, mounting and changing (or swapping) filters in and out of a light path. The UFC can be used for imaging where you may want to swap different filters (e.g. LRGB) between a camera and a telescope but do not want the bulk, or expense, of a filter wheel. The UFC can be used between a camera and a Celestron RASA 11/14(36) or a Starizona Hyperstar system where the overall size and shape of a filterwheel causes issues. You can also use the UFC for visual purposes where you can easily switch between different colour filters between a telescope and an eyepiece. We'll discuss more on the different uses of the UFC in a future blog.

In this first blog we will give a general brief introductory overview of the UFC system, and then follow with other blogs that cover in more detail: 

• Base Unit
• Filter slider
• Telescope-side connections
• Camera-side connections
• Usage and other use examples

The image below shows the standard "exploded" diagram of the parts that make up the Baader UFC. We've colour-coded it to highlight the main different parts (see below). At present there are 30+ parts to the whole UFC system in total. The large number of components may seem somewhat overwhelming at first glance, and can lead to some confusion, and that the system is complicated. However, we hope this series of blogs will help show how simple, and effective, the UFC is.

 The Baader UFC system

The Baader UFC is really quite simple. Although looking at the diagram above it looks complicated and crowded....you will only really need.....four (4)....main parts! We have colour coded each section in the diagram above to make it easier to understand. To put it simply, you will need: a camera-side adaptor (part #1) and a telescope-side adaptor (part #2) in addition to the core part of the system called the UFC Base unit (part #3) and then a sliding filter drawer for your filter (part #4). 

If we simplify the above diagram further to make things a little to make it "easier on the eye" we get the diagram below.

• The filter changer - or UFC base unit: This is at the heart/centre/core of the Baader UFC System and is the part that all else in the UFC system is attached to. It allows a range of adaptors for different cameras to be attached on one side, with different telescope adaptors to be attached on the opposite side. The base unit is also designed to accept one of three different filter slider drawers to be inserted and removed. 

• Filter drawer slider - there are 3 versions available to accommodate different size filters. 
• 2" M48 for 2" mounted filters
• 50.4mm for unmounted filters
• 50x50mm square for square unmounted filters

• Camera-side adaptor: There are currently nine (9) of these adaptors to fit a variety of different cameras and you choose the one to fit your camera - see your camera specifications/manual. The adaptors have a male threads (except the FLI adaptor) to screw into your camera body, or you can attach a T-ring. These camera adaptors have two (2) sets of four (4) countersunk holes (and come supplied with screws) to securely fix them to the camera side of the UFC base unit. 

• Telescope-side adaptor: There are nine (9) of the telescope side adaptors and have female threads to attach to a male component (e.g. T-2 Male adaptor or M48 reducer/flattener). The RASA adaptor attaches to the front of the Celestron RASA lens assembly housing plate and is secured by the knurled locking ring on the RASA lens assembly (more on this in a later blog).