The power 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 distances required: 2x = 42 mm, 3x = 96.2 mm, 4x = 150 mm, 5x = 206.4 mm, 6x = 259 mm, 7x = 314 mm, 8x = 368 mm.
Visual
When using the Astro-Physics Maxbright Diagonal, we suggest one of the following configurations:
- Basic Set: ADAT2 (Astro-Physics 2"/T2 adapter) + BPFFC (FFC) + AP16T
(2"/T-2 nosepiece)
or
- FFC system components: BP17 (2" adapter) + BP28 (expanding ring)
+ BP6/7 (T-2 changer
system) + BPFFC (FFC) + BP16 (T-2 nosepiece)
BP17 | $64.00 | in stock |  |
BP28 | $45.00 | in stock |  |
BP6/7 | $88.00 | in stock |  |
Using either the "Basic Set" or the "FFC System Components" in front of the AP Maxbright Diagonal, the eyepiece focal plane will be effectively 152 mm (+/-10% depending on the style of the eyepiece) behind the BPFFC for an approximate 4x magnification. To get an exact measure of power requires the exact position of the eyepiece field stop with respect to the rear flange of the BPFFC. Using various extension tubes, the power can be increased to 8x, assuming that your telescope focuser has sufficient in-travel to allow this configuration to come to focus.
Lower powers can be achieved by placing either the “Basic Set” or the “FFC System Components” into the AP Maxbright Diagonal and then adding the eyepiece. This setup will place the focal plane approximately 50 mm behind the BPFFC, yielding about 2x magnification. The magnification will vary somewhat with eyepiece design.
35 mm Camera
35 mm SLR and DSLR cameras have a 55 mm spacing distance to the film/sensor plane when using a T-ring system. The lowest magnification of 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 - 320 mm of extension tube(s).
If you use the 2" Astro-Physics Adapter (ADAT2) and a 2" Astro-Physics Prime Focus Camera Adapter (part # starting with PFC or PFCT), the distance to the film plane will be 140 mm for 3.7x magnification.
ADAT2 | $40.00 | in stock |  |
BPFFC | $793.00 | in stock |  |
PFCT | $50.00 | in stock |  |
PFCTCAN | $70.00 | in stock |  |
PFCTEOS | $70.00 | NO LONGER AVAILABLE |  |
PFCTKON | $70.00 | in stock |  |
PFCTMAF | $70.00 | in stock |  |
PFCTMIN | $70.00 | in stock |  |
PFCTNIK | $70.00 | in stock |  |
PFCTOLY | $70.00 | in stock |  |
PFCTPTK | $70.00 | NO LONGER AVAILABLE |  |
PFCTPTS | $70.00 | in stock |  |
6x7 Camera
To use a medium format camera requires the Baader M68 Quick Change System and the appropriate adapters and extension tubes. The lowest power without extension tubes will be between 3x and 3.3x depending on camera type: Hasselblad: 74.9 mm and Pentax 67: 84.95 mm.
CCD Camera
The FFC system allows you to achieve various powers with your CCD Cameras
(such as the
ST-7/8/9/10 or the STL-11000). 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. By inserting the 2"
nosepiece of your CCD Camera (with color filter wheel closely coupled) directly into the Astro-Physics 2"/T2 Adapter (ADAT2), which
you have attached to the back of the BPFFC, the power will be approximately
3x. This will increase with the addition of extensions or other intermediate
accessories.
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