Celestron 94175 Focal Reducer & Field Corrector, vermindert brandpuntafstandlengte en -ratio 37% – f/10 tot f/6.3 – Voor deepsky-objecten en astroimaging, werkt met Schmidt-Cassegrain-telescopen

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

Bought this as return with unspecified minor flaws. Turned out to be just some crap on the lens that easily wiped off. If you own a Celestron C8 and want to see the entire moon its a must-have.

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.

Der Reducer macht bei mir alles richtig. Das Bild bleibt zum Rand hin deutlich schärfer und hat keine auffällige Verzeichnung, Krümmung mehr. Bis jetzt sehr zufrieden.

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."

Does exactly what it should. I needed to reduce my magnification to be able to see the whole moon. This works