Celestron f/6.3 Reducer Corrector & Aux Port Splitter - Dual Purpose

In this review the focus is on a practical combo for Celestron C-series users: the f/6.3 Reducer/Corrector and the Aux Port Splitter. The bottom line is straightforward: if you own a C5 through C14 Schmidt-Cassegrain telescope and do astrophotography or need a second AUX connection on a computerized mount, this pair adds noticeably wider fields of view and convenient control expansion without compromising image quality. The reviewer found the reducer speeds imaging and maintains sharpness, while the splitter removes a common port limitation on many mounts.

Key Features

• Dual focal ratio: The reducer/corrector provides an f/6.3 focal ratio for C5-C11 and f/7 for the C14, letting users switch between longer and shorter effective focal lengths.
• Improved imaging speed: By reducing the focal ratio the accessory can shorten exposure times by roughly a factor of three for deep-sky astrophotography.
• Wide field of view: The corrector delivers noticeably wider fields, making large nebulae and star fields easier to capture on small sensors.
• Precision construction: Made in Japan, the reducer/corrector is built to match the optical tolerances of Schmidt-Cassegrain telescopes and keep aberrations under control.
• Auxiliary port expansion: The Aux Port Splitter adds an extra 6-pin AUX output to mounts that have a single built-in port, enabling simultaneous use of two aux devices.
• Simple connectivity: The splitter uses a single 6-pin input and provides two 6-pin outputs in a compact adapter package for tidy cable routing.

Who It's For

This combo is aimed at amateur astronomers and astrophotographers who own Celestron C-series Schmidt-Cassegrain telescopes and want faster imaging and a wider field without changing telescopes. It is especially useful for owners of C5, C6, C8, C9.25 and C11 telescopes who want an f/6.3 option and for anyone shooting extended deep-sky targets.

It is less suitable for visual observers who prioritize maximum native contrast at very high magnifications or for those using mounts that already have multiple auxiliary ports. Professionals needing custom optical solutions should consider dedicated reducers or custom mounts instead.

Pros & Cons

Pros

• Reduces exposure time significantly, making astrophotography more efficient.
• Provides a much wider field of view that many customers reported as improving composition for deep-sky targets.
• High-quality fit and finish with components made in Japan, giving reliable mechanical performance.
• Aux Port Splitter solves the common problem of a single AUX port on many computerized mounts.

Cons

• The change in focal ratio can alter contrast and central obstruction effects compared with native longer focal ratios.
• The splitter is an adapter only and does not add powered or advanced control features beyond duplicating the AUX connection.

Specifications

Product type	Reducer/Corrector and Aux Port Splitter combo
Compatible telescopes	C5, C6, C8, C9.25, C11, C14 Schmidt-Cassegrain
Focal ratio	f/6.3 for C5-C11; f/7 for C14
Astrophotography benefit	Reduces exposure time by about a factor of 3
Aux connector	One 6-pin input; two 6-pin outputs
Origin	Reducer/Corrector made in Japan

Our Verdict

For C-series owners who photograph the deep sky or want a wider field, this reducer/corrector and AUX splitter bundle is a practical, value-focused upgrade. The reducer speeds imaging and preserves usable image quality, while the splitter fixes a common mount limitation, making the pair a smart, compact addition to many setups.

Frequently Asked Questions

Will the reducer work on my C8?
Yes; the reducer/corrector is specified to work on C5 through C11 models, giving f/6.3 performance on a C8.

Does the splitter add any power or control features?
No; the Aux Port Splitter simply provides two 6-pin auxiliary outputs from one 6-pin input to allow two devices to be connected.

Does using the reducer harm image quality?
When used as intended it preserves image quality while widening the field, though the change in focal ratio can affect contrast and central obstruction compared with the native configuration.