2.7" Prime Focus Field Flattener for 130 f/6.3 StarFire GT with Original 2.7" Focuser (13027FF-GT)

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Approximately one week after your order.

December 2022 - This field flattener was introduced to optimize performance of the 130 f6.3 StarFire GT with its original 2.7" focuser.  If your GT refractor was upgraded to the 3.5" focuser, you will need 13035FF-2.

Field flatteners are designed to accurately compensate for the inherent field curvature of a refractor lens. For each lens design there is an optimal spacing that works best for sharp focus over the specified field size. As camera designs have advanced, the performance requirements have become more stringent. This is now especially important when using the newest CMOS cameras with pixel sizes of 3.76 microns and smaller. For this reason, 67PF562 has been replaced by this new design. However, if your camera has larger pixels, the 67PF562 will perform very well.

The backfocus spacing for these flatteners (as measured from the rear flange) is 3.4" +/- 1/10" (86.4 mm +/- 2.5 mm).

The bayonet male thread size at the rear is 3.725" x 24.

Use the bayonet locking ring to secure your camera into position after you have framed your image. This allows you to rotate the camera to achieve your desired composition.

Field of View with 130 StarFire GX (with 2.7" Focuser)

Fully Illuminated Circle
35 mm Full Frame CCD

2.6” (65 mm)
18.0 x 13.5 mm
22.3 x 14.9 mm
36 x 24 mm
36.8 x 36.8 mm

4.3° (256 min.)
1.2° x .88° (71 x 53 min.)
1.5 ° x .98° (88 x 59 min.)
2.4° x 1.6° (142 x 97 min.)
2.4° x 2.4° (146 x 146 min.)


35 mm SLR or DSLR Camera - For full frame Canon and Nikon DSLR's, we offer the Large 1.875" diameter SLR Adapter with Canon EOS (67RLEOS) and Nikon (67RLNIK) Bayonets .

CCD Camera - Choose the appropriate adapter to space the field flattener properly with your CCD camera.  Consult the Diagrams and Instruction Sheets below for a wide variety of options. 

13027FF-GT Includes

  • Field Flattener housing with optics optimized for this version
  • Two beautifully machined and black anodized covers
  • 13027FF-GT Decal to differentiate from prior versions. 

Select the Appropriate Adapter to Use with Your Camera

  • Canon EOS Camera Adapter with large 1.875" (47.6mm) diameter stainless steel bayonet for auto-focus EOS SLR cameras. To be used with 2.7" and 4" Field Flatteners (67RLEOS)
  • Nikon Camera Adapter with large 1.73" (44mm) diameter stainless steel bayonet. To be used with 2.7" and 4" Prime Focus Field Flatteners (67RLNIK)
  • 0.5" CCD Adapter for older SBIG ST configurations with gap-mounted color filter wheel and for use with extensions to create intermediate spacings (A1260)
  • 2.7" Spacer Rings , Set of 3 Rings (SRSET-27)
  • Step-Down Adapter with 2.7" Male Threads to 42mm Male Threads (ADA27-42)

  • Step-Down Adapter with 2.7" Male Threads to 48mm Male Threads (ADA27-48)
  • Step-Down Adapter with 2.7" Male Threads to 54mm Male Threads (ADA27-54)
  • Step-Down Adapter with 2.7" Male Threads to 68mm Male Threads (ADA27-68)
  • Step-Down Adapter with 2.7" Male Threads to 2.156" Male Threads (ADA27-2156)
  • 2" Adapter to use SCT accessories - for 2.7" drawtubes (ADA204)

  • 2" Adapter with Brass Locking Ring (ADA2003A)
  • Thin 2" Adapter with brass locking ring and 3 large thumbscrews. Use when you need 11/32" more in-travel. (ADA20132)
  • 2"/T-2 Tapered Nosepiece for CCD Cameras, SBIG ST7, Baader Planetarium Giant Binocular Viewer or any item with T-2 threads (AP16T)
  • 2" Nosepiece with 2.156" Threads for QSI and SBIG CCD Cameras and 48mm Filter Threads (A2558)

Diagrams and Instructions

Custom Adapters

If you need an adapter that is not listed above, we recommend that you contact PreciseParts. Refer to the link for the spacing requirements document above.

Important Note: These flatteners will look very similar to the previous 67PF562 version. The 13027FF-GT decal will be critical for differentiating one from the other.