Celestron 94175 Focal Reducer & Field Corrector Imaging Accessory, Reduces Focal Length & Ratio 37% – f/10 to f/6.3. For Schmidt-Cassegrain Telescopes

I have Celestron C8, this has a focal ratio of F/10. You don't necessarily need to know what that means but Astrophotographers would describe this as a "slow" ratio. Great for planetary obsevation. For nebulae, star clusters etc, still a great all-rounder, but some nebulae are quite large and/or diffuse. The focal reducer gives F/6.3. (faster). This means a wider and brighter field, though magnification can be applied to it, as normal. The Pleiades are almost all available in a low powered eyepiece, the moon is fully observable. When I went comet hunting, it gave me a better all-around view, before zooming in for the Nucleus and Coma. This may be classed as a luxury item, but it Does enrich the brightness and gives wider angle vistas. There are comments that it flattens the field. This means that at the margins of the view, in an SCT, the stellar points of light, can become slightly elongated. This is corrected with this lens. A good purchase for me, I would recomend, a good astronomer's tool, gives options. Is easy to add and take off the Telescope tube, in low light, thanks to the solid/well spaced screw thread.

The reducer and corrector is perfect for my Celestron 11SCT as it increases the FOV meaning I can get objects like the Perseus Double in a single 40mm 1.25" eyepeice as well as both the Bode's galaxies. Only downside is it doesn't work with my 2" star diagonal as it won't focus with both attached but works great with a 1.25" star diagonal.

A must have for anyone with a scope. You don’t realise how much you need it until you have it.

Improves the field of view of my 8SE, allowing decent photography of larger DSOs (particularly M42), when using a large sensor (APS-C), stars toward the edge are much smaller, rounder and more point like, but not perfect, there is also some strong vignetting, but this can be dealt with using calibration frames.

This seems to work well on my 1970s celestron classic orange tube c8. From what I have seen weather permitting it’s seems to work well. But the weather in the uk has been mixed back over the months and not had a good long time to test the item. But in a short test it’s working well.

Good price including postage and packaging. I am yet to use it however. I needed the item to increase field of view for larger field images such as galaxies etc. The item arrived on time and was well packaged (and sealed) and all is as expected.

Helps get more of the planets and moons in one picture. Used with a Celestron 8SE

Purchased for 5SE telescope in order to be able to use eyepieces set 3,5 - 14mm. In particular to be able to use 3,5 and 5mm lenses which without the reducer produce too big magnification fore the f/10 scope. It did work and for a 'made in China' product it is an exceptional quality item. The glass is spotless and the paint is of the highest standard. No engravings etc. but for the price - no issues with the quality at all. So? What is the problem? Well, I am not an expert in optical field but there seem to be an internal reflection issue when looking at bright objects. In particular, when the moon goes into the field of view a light glare appears and it only goes away when the moon is in the very centre of the view. Moving away from the centre, an irregular shape appears again and it is very disturbing. My scope may be slightly out of collimation but without the reduced this effect is negligible. With the reducer - very strong. It may be a very good product but I would not recommend it for a 5 inch scope.

Bought for my Celestron C5. Works well, nicely machined, solid and let's you have two telescopes for the price of one!

Fantastisches Teil für großere SC Teleskope. Scharfes Bild bei der empfohlenen Abstand zu Kamera Chip von 105mm. Die Korrektion am Rand ist für mein Geschmack besser als bei der Antares Variante, eventuell bei mir der Fall, da ich ein Celestron besitze.

I am sorry that I did not buy this accessory two years ago. It all began with a used Celestron C5. Then I bought a very nice used Nexstar 8SE and thought wow, I should have done this go-to thing sooner. After a year or so, I moved up to a new Celestron CPC925 and decided to explore video astronomy with an inexpensive Samsung SBC-2000 security cam. Most SCTs have a focal ratio of about f/10 (focal length divided by aperture) but a camera works better with a faster (shorter focal length) scope. The usual way to do that with a video camera is to screw on a small .5x reducer. So I bought on of those for $35 and was just amazed at the detail and colors in the Dumbbell Nebula. Then someone over at Cloudynights.com suggested that try adding a f/6.3 reducer (stacking reducers). So I bought the f/6.3, screwed in on the back of the CPC925, replaced the visual back and diagonal, mounted the camera (without the .5x) and stayed up until 2AM looking at the Orion Nebula. Before heading for bed, I pulled the camera, put in a 20MM 68 degree APOV eyepiece, and had another "Wow!" moment. The Celestron f/6.3 reducer-corrector really brightens the image, widens the field of view, improves contrast and detail, and flattens the image improving the look of stars near the edge of the field of view. Many people leave them on all of the time except when looking at the moon and planets or other high magnification situation. There are other and cheaper reducers on the market and they do work. However not all of them offer the same degree of improvement at the edge of the field of view. Rod Mollise writes "...6.3 r/cs are one of the best--if not the best--SCT accessories to ever come down the pike" and "I'll put it this way...the 6.3 rarely comes off the rear cell of the C8."

Ainda não tive a oportunidade para utilizar. Mas o produto parece ser de boa qualidade, bem construído, em alumínio fundido e pintado, lente multi-coated.

Puedo decir sin temor a equivocarme que el aditamento ha superado con creces mis expectativas. La corrección de campo que hace es espectacular, mejora mucho la imagen y además ha vuelto a mi C11 en un telescopio súper luminoso. Probadísimo de manera muy satisfactoria en visual, y asumo que se comporta igual de maravilloso en fotografía, sólo que yo personalmente no he podido probarlo en ese rubro dado que mi aparato es de la serie CPC y por lo tanto tiene montura AZ y no cuento ni siquiera con una cuña ecuatorial para intentar hacer alguna foto de cielo profundo. Pero en visual, mis respetos para ese reductor de focal. Lo recomiendo mucho.