Celestron Reducer - Corrector f/6.3
|The Celestron f/6.3 focal reducer threads onto any Celestron or Meade Schmidt-Cassegrain telescope and produces a wider field for astrophotography. |
The Celestron f/6.3 focal reducer threads onto any Celestron or Meade Schmidt-Cassegrain telescope and produces a wider field for astrophotography. The output side is a male SCT-thread., therefore, any existing accessories will simply thread onto this device. The primary application of this product is astro-imaging, but some people do use it as a substitute for two-inch eyepieces. The f/6.3 focal reducer compresses the light cone exiting the telescope to 63% of it's original size. This effectively increases the field of view as seen by a CCD camera, and also serves to shorten exposure times.
There is a common misconception that a focal reducer can serve to increase field of view of a Schmidt-Cassegrain telescope. While this is true when used in combination with 1.25" eyepieces, the same is not generally true with 2" eyepieces. Use of 2" eyepieces with this product will result in vignetting of the image, with the effect becoming increasingly pronounced as the eyepiece field stop increases above 27mm. Simply stated, the field of view will not get larger because there is no available light cone to support this.