The FFC System (also known as the Astro T-2 System) offers a wide array of adapters to suit a variety of needs (also see: Standard FFC Combinations). Astro-Physics has also manufactured a 2"/T-2 Adapter with brass locking ring (ADAT2) to simplify the system (it takes the place of several components). The Basic Set couples the 2"/T-2 Tapered Nosepiece (AP16T) to the front of the BPFFC optic and the 2"/T-2 Adapter with brass locking ring (ADAT2) to the back, allowing a simple method for using visual and photographic accessories.
|Shown from left to right:
AP16T - 2"/T-2 Tapered Nosepiece (fits into 2" openings). This item helps you to come to focus when the FFC is inserted directly into your refractor or SCT (not used for Newtonians).
BPFFC - Fluorite Flatfield Converter Barlow
ADAT2 - 2"/T-2 Adapter with brass locking ring (manufactured by Astro-Physics, not shown on FFC System diagrams)
- BP25A - T-2 Extension Tube, 15 mm long
- BP25B - T-2 Extension Tube, 40 mm long
- BP25C - T-2 Extension Tube, 7.5 mm long
Achieving Various Magnifications with the BPFFC
The magnification of the BPFFC will vary depending on the distance to the focal plane behind the Barlow. As the spacing increases, so does the magnification. However, remember that as you increase the spacing (magnification) you also will need to shift the BPFFC forward in the focuser. The amount of in-travel available becomes a consideration as you reach towards the higher magnifications. The following is a list of the magnifications and the back spacing required: 2x = 42 mm, 3x = 96.2 mm, 4x = 150 mm, 5x = 206.4 mm, 6x = 259 mm, 7x = 314 mm, 8x = 368 mm.
Link to BPFFC Magnification Explanation.
Link to BARCON & BPFFC Magnification Graph.
When using the Astro-Physics Maxbright Diagonal, we suggest one of the following configurations:
Basic Set: AP16T (2"/T-2 nosepiece) + BPFFC (FFC) + ADAT2 (Astro-Physics 2"/T-2 adapter)
FFC system components: BP16 (T-2 nosepiece) + BP6/7 (T-2 changer system) + BPFFC (FFC) + BP28 (expanding ring) + BP17 (2" adapter)
Magnifications as low as 2x can be achieved by placing either the “Basic Set" or the “FFC System Components" into the AP Maxbright Diagonal and then adding the eyepiece. The magnification will vary somewhat with eyepiece design.
Using either the "Basic Set" or the "FFC System Components" in front of the AP Maxbright Diagonal will yield approximately 4x magnification. Various extension tubes can be added to increase the magnification to 8x, assuming that your telescope focuser has sufficient in-travel to allow this configuration to achieve focus.
DSLR/SLR cameras have a 55 mm spacing distance to the film/sensor plane when using a T-ring system. The lowest magnification of approximately 2x is achieved by threading a standard T-ring directly to the back of the BPFFC body (without a 2" adapter).
3x to 8x magnifications are achieved by adding 50 mm to 320 mm. It is recommended to use the A3511 and 2.7" extension tubes to achieve these lengths. As above, this assumes that your telescope focuser has sufficient in-travel to allow this configuration to achieve focus.
The FFC system allows you to achieve various magnifications with your CCD Camera. If you thread the BPFFC directly into your camera (without the 2" nosepiece or with a custom low profile adapter) the lowest possible magnification will be approximately 2x.
Similarly, 3x to 8x magnifications are achieved by adding 50 mm to 320 mm. It is recommended to use the A3511 and 2.7" extension tubes to achieve these lengths. Again, it is assumed that your telescope focuser has sufficient in-travel to allow this configuration to achieve focus.
Tips for Using the FFC System with Various Telescopes
There are several options for attaching the BPFFC to your telescope.
Basic Set: If you have an 8 or 9.25" SCT, use our ADASCT, which was designed for 2" slip-in accessories and features our brass locking ring. We have also developed the ADASCTLC and ADASCTLM, which are larger versions designed for SCTs that are 10" or larger. This adapter takes advantage of the 3.25" opening of these scopes.
When inserted into a 2" focuser on a Newtonian telescope, the Baader FFC Barlow will require an additional 1 inch of in-travel to allow focus at 2x magnification. More travel is required for higher powers. To use, slip the FFC directly into your focuser. Tighten the focuser screw on the smooth surface of the FFC between the ridges. You will also need our ADAT2 (and possibly a 1.25" adapter) for your eyepiece.
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