Celestron F/6.3 reducer/corrector for Schmidt-Cassegrains


Availability: In stock

This combination f/6.3 focal reducer and field corrector works with all Celestron 5" through 14" Schmidt-Cassegrain telescopes, as well as all Meade 8" through 16" SCTs . . .
Our Product #: 8325
Celestron Product #: 94175

Product Description

This combination focal reducer and field flattener consists of a four-element multicoated 41mm lens in a metal cell. It threads onto the rear cell of 5" to 16" Celestron and Meade Schmidt-Cassegrain telescopes, making it possible to have a dual focal ratio instrument without sacrificing image quality. The reducer/corrector duplicates the rear cell thread of the telescope, allowing you to attach all standard rear cell visual and photographic accessories. The reducer/corrector converts the f/10 focal ratio of Celestron C5, C8, C9¼, and C11 telescopes (and all Meade 8" and larger f/10 telescopes) to f/6.3. The f/11 C14 telescope becomes an f/7. When used for astrophotography, it reduces exposure times by a factor of 3, with an actual field diameter of 1.5" at the film plane.

The reducer/corrector is supplied with full instructions and with plastic dust caps for both sides of the lens assembly. A rubber grip ring on the body allows for easy installation of the reducer on your scope, even when you are wearing gloves.

Tech Details

Warranty 2 years


Review by:
Good Product. I got good wide (ish) views allowing me to easily see a number of objects with my Evolution 8, which would not have been possible otherwise. Included lens covers stay on w/ being too tight. (Posted on 1/7/2019)
Review by:
I use this reducer/corrector on my C11 scope and have imaged with it using APS-C sized sensors and smaller for planetary images and globular clusters. It provides crisp images all the way to the corners for micro-four-thirds sensors sizes and smaller, but APS-C sensors see some fairly heavy aberrations in the extreme corners. I've heard that Starizona's SCT Corrector does a better job, but it is also four times as expensive. For the price, this reducer/corrector does a good job. (Posted on 1/5/2019)
Review by:
If you buy no other accessory for astrophotography, A 6.3 reducer is essential for imaging DSOs with a cassegrain. It will flatten your field and give you FAR Shorter exposure times. This is essential when dealing with dim targets and the long focal lengths of a cassegrain. I have used the 6.3 Celestron reducer/flattener and it has performed flawlessly on my c9.25. If you plan to image DSOs or large targets like the Moon, You already know you need this :) This has served me well for many years of imaging and visual. A Must have Accessory for a SCT (Posted on 11/29/2018)
Review by:
Serves its function. helps make a brighter and more wide view look to your 1500mm scope. I use it on a Celestron C-6 and you get a better view of the moon with this focal reducer. You get a flatter field also for astrophotography. Handy little lens accessory. Have it on most of the time. (Posted on 11/14/2018)
Review by:
Works great for reducing the focal length of my Celestron SCT! Use it both visually and for photos! (Posted on 11/4/2018)
Review by:
I find this significantly improves the cleanness of views in my C6 and C9.25. Spacing may need to be tinkered with for different diagonals and EPs for best results. I use DeLites in my C6 and find C9.25 views sharp to the edge with the reducer + Morpheus oculars. (Posted on 10/26/2018)
Review by:
Whilst the correction is not perfect, it does greatly increase the usable area for astrophotography on my 6SE (not to mention substantially increasing the field of view for larger targets like Orion/M42 or the full moon).

Good reducer/corrector for the price. (Posted on 10/15/2018)
Review by:
Very pleased with this item that I bought for my 8” SCT. Only used it for visual at this stage but I plan on getting a camera very soon and will be employing it to give a wider field of view and crisp flat images! Very good optics! (Posted on 10/7/2018)
Review by:
Here’s an amazing way to get maximum field of view out of a C8 while using only 1.25” oculars. Use it under dark sky with an ES68 24mm and you’ll get a beautiful view of large targets like the Orion Nebula or the Andromeda galaxy. As a positive side effect, it will somewhat flattens the center of tge field (but the extreme border will still remain a bit out of focus if you focus in the center). For a perfect flat field to the edge optic, you’ll need an EdgeHD sct. This accessory gets you halfway there for a lot less money. (Posted on 10/6/2018)
Review by:
While the build quality of this reducer/corrector is very good it doesn't work with all the telescopes Celestron claims. Or at least it doesn't work well with my older Celestron C8. I think the problem is that over the years Celestron has used different backs to the telescopes which require different length spacers.

It does work very well for visual use on all Celestron Schmidt Cassegrains,. (Posted on 10/6/2018)
Review by:
I've had this focal reducer for at least 12 years and it works great with my LXD55 SC-8. It reduces it from an f/10 to f/6.3 and it also flattens the field so the stars near the edge are more pinpoint.
It threads on very easily to the back of the OTA and I simply thread my diagonal onto it. A great accessory to have! (Posted on 10/6/2018)
Review by:
I have owned this Celestron R/C for 8 years now, and it continues to perform very well. I recently used it on my Astrotech AT66 refractor and to my surprise it flattened the field and gave F4 speed on it. The field is at least 90% corrected and photographic field is greatly augmented.

Good reducer corrector, especially for its price.

Clear skies,
Javier Villarreal (Posted on 8/4/2017)
Review by:
I think this is the first accessory one should buy for an f10 SCT. I use it on a Meade 10" and a Celestron 6", for both visual and photographic observation. With a 40mm 45 degree FOV eyepiece, I get almost a 2 degree field in the smaller scope, and a degree in the larger one. Very quick to install and remove, and the optics are superb. (Posted on 8/4/2017)
Review by:
This really is a handy little device. I do not do astrophotography so I do not need it for shorter exposure times, but I do use it to double the use of my eyepieces, similar to how one would use a barlow lens but with the opposite effect. With this, my 8 SE goes from a 2032mm f/10 scope to a 1280mm f/6.3 scope. This allows my 17mm Ethos to have magnifications of 120x at 2032mm, and 75x at 1280mm. My 13mm Ethos goes from 156x at 2032mm to 98x at 1280mm. You get the idea. Using this focal reducer really expands the capabilities of the telescope. I highly recommend it if you want to give more flexibility to your eyepiece collection for lower-power viewing. (Posted on 8/4/2017)
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