Optical reference
Celestron Astro Fi 130: aperture, focal length and eyepiece fit
What the Celestron Astro Fi 130 measures, the magnification and true field each eyepiece produces in it, and the barrel, mount payload and camera adapter that fit.
Published specifications
Eyepiece ladder
2 pairings| Pairing | Magnification | True field |
|---|---|---|
| Tele Vue 3.5mm Nagler Type 6 in the Celestron Astro Fi 130 | 186x | 0.44 deg |
| Tele Vue 10mm Delos in the Celestron Astro Fi 130 | 65x | 1.11 deg |
The Astro Fi 130 is a fast 130 mm f/5 Newtonian on a WiFi GoTo mount. The short 650 mm focal length gives wide, bright low-power fields and needs short eyepieces to reach high magnification.
Because magnification is the telescope's 650 mm focal length divided by the eyepiece focal length, a 25 mm eyepiece gives 26x here and a 10 mm eyepiece gives 65x. The highest useful magnification is the published 307x, beyond which the image dims and softens without showing more detail.
The focuser takes 1.25 in eyepieces, so use 1.25 in eyepieces; a long low-power 2 in eyepiece will not fit this focuser.