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Starizona Apex ED 0.65x Focal Reducer & Field Flattener - Short Version

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SKU: STZ-APEXED-S
$449.00
 

Starizona Apex ED 0.65x Reducer/Flattener

This Apex ED Focal Reducer/Field Flattener with 5-element design from Starizona shortens the effective focal length of apochromatic refractors popular with astrophotographers, as well as Ritchey-Chretien (RC) and Meade Advanced Coma Free (ACF) telescopes by a factor of 0.65x. In addition, pinpoint star images are produced as a result of using this reducer due to its correction for the field curvature and astigmatism common to apo doublet and triplet refractors, and RC/ACF telescopes.

By using this Starizona Apex ED Reducer, you can turn an f/5.5 apo refractor into a super fast f/3.6 astrograph imaging system. Slower f/9 RC telescopes are transformed into much speedier f/5.9 instruments. The reduction factor produces a 1.5x wider field of view and 2.4x shorter exposure times.

The Apex ED Reducer features extra-low disperion glass to eliminate chromatic aberration and to provide sharp star images over a 30 mm image circle, capable of working with most popular CCD, CMOS and DSLR cameras up to APS-C format.

Compatible with standard 2" focusers, the Apex ED Reducer contains M42 T-threads on the camera side, but is also capable of accepting standard 2" (M48) filters on the telescope side for convenient light pollution filter use. For Meade ACF telescopes, the ApexED Reducer attaches with the help of a 2" visual back.

An optional threaded adapter is available for select refractors to allow direct threaded attachment of the ApexED Reducer for eliminating the possibility of tilt introduced by the standard focuser clamp ring.

Long "L" and Short "S" Versions

Two separate versions of the lens, an "L" version and an "S" version, are available for getting optimized performance from the Apex ED. The "L" version works with 500 mm and longer focal length telescopes, including most 100 mm and higher refactors, as well as all RC and ACF telescope models. Meanwhile, the "S" version is suitable for use with telescopes that have focal lengths ranging from 300 mm to 500 mm which includes the majority of 60-80 mm apochromatic refractors.

Backfocus

The nominal backfocus distance from the Apex ED Reducer's T-threads to the image sensor depends slightly on the focal length of the telescope. It is at least 55 mm in all configurations. Optimum backfocus for various focal lengths can be found below. Please contact us for help in choosing the right adapters or spacers necessary for your setup.

Apex ED L

  • 500-600 mm Focal Length: 58 mm Backfocus
  • 600-700 mm: 57 mm
  • 700-900 mm: 56 mm
  • >900 mm: 55 mm

Apex ED S

  • <350 mm Focal Length: 62 mm Backfocus
  • 350-450 mm: 60 mm
  • 450-500 mm: 59 mm