Optical reference
Orion SpaceProbe 130ST: aperture, focal length and eyepiece fit
What the Orion SpaceProbe 130ST 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 Orion SpaceProbe 130ST | 186x | 0.44 deg |
| Tele Vue 10mm Delos in the Orion SpaceProbe 130ST | 65x | 1.11 deg |
The SpaceProbe 130ST is a short-tube 130 mm f/5 Newtonian on a light equatorial mount. The 650 mm focal length gives wide, bright low-power fields and needs short eyepieces for 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 about 260x (roughly twice the aperture in millimetres), 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.