Telescope-Accessories-Starizona SCT Corrector 4 – 0.63x Reducer and Coma Corrector

Starizona SCT Corrector 4
0.63x Focal Reducer/Coma Corrector

The Starizona SCT Corrector is a focal reducer and field-flattener/coma-corrector for standard Schmidt-Cassegrain telescopes. It converts the telescope from f/10 to f/6.3, resulting in a wider field and faster imaging. Imaging at f/6.3 is 2.5 times faster than f/10!

The field is optimized for a 27 mm image circle. Spot sizes are up to 6 times smaller than the native telescope, and coma is completely eliminated. The result is much sharper stars across a large, flat field of view. A standard 2″ barrel allows a variety of telescope attachment options. Curious to learn more? Check out the comprehensive video below!

Note that since the SCT Corrector is designed to eliminate the coma inherent in standard f/10 Schmidt-Cassegrain telescopes, it will not work with coma-free designs like the Celestron Edge HD or Meade ACF telescopes.

Focal Length

The precise focal length of this reducer/corrector and telescope combination is somewhat contingent upon the exact placement of the SCT Corrector lens in the optical path. This will theoretically be within a few millimeters of the telescope’s rear threads. Adjusting this distance should not have any impact on the optical quality, only the focal length. The nominal focal lengths for individual Celestron SCTs are listed below. Additionally, even though the SCT Corrector is also an excellent fit for standard Meade f/10 Schmidt-Cassegrains, Starizona does not have precise data regarding the nominal designs of those scopes.

• C6: Focal Length: 1220 mm  Focal Ratio: f/8

• C8: Focal Length: 1450 mm  Focal Ratio: f/6.8

• C9.25: Focal Length: 1490 mm  Focal Ratio: f/6.3

• C11: Focal Length: 1760 mm  Focal Ratio: f/6.3

• C14: Focal Length: 2365 mm  Focal Ratio: f/6.7

Please Note: The reduction ratio is different for the C6 and C8 because the native backfocus of those telescopes is less than that for the larger scopes, so there is slightly less reduction. The C14 is slightly slower because it is natively f/11.

Camera Adapters

With a 27 mm optimized image circle, the Starizona Corrector 4 will accommodate most APS-C astronomy cameras and DSLRs.

The backfocus of the SCT Corrector IV is 90.3 mm with a +/- 2 mm tolerance. Smaller format cameras may work at slightly larger tolerances. The backfocus is measured from the base of the threads of the SCT Corrector to the camera sensor. The SCT Corrector IV comes with a 35.3 mm adapter with M42 male threads on the camera side and provides a standard 55 mm backfocus.

Starizona offers a wide variety of camera adapters that will work with this corrector. If you are unsure about the camera configuration, please contact High Point technical support for help.

Telescope Adapters

The 2″ barrel on the Starizona SCT Corrector fits 2″ visual backs and focusers.

Filters

Threaded to accept 2″ or 48 mm filters.

Highlights

• Focal Reduction Factor: 0.63x

• 2.5 times faster than the inherent SCT f/10

• 1.4 times faster than the initial design for the f/7.5 SCT corrector

• Image Circle: 27 mm

• Barrel: 2″

• Accepts: 2″ or 48 mm filters

• SCT Corrector Top Thread: M42x0.75 mm T-thread

• Material: Black anodized, machined aluminum housing

• Optics: Fully multi-coated

• Optical Design: 4-element