Optical reference
Celestron C6 optical tube: aperture, focal length and eyepiece fit
What the Celestron C6 optical tube 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 |
|---|---|---|
| Celestron Omni 6mm Plossl in the Celestron C6 optical tube | 250x | 0.2 deg |
| Celestron Omni 15mm Plossl in the Celestron C6 optical tube | 100x | 0.5 deg |
The C6 is the bare 150 mm f/10 SCT tube behind the 6SE. Sold without a mount, it drops onto any Vixen-dovetail head and is a common grab-and-go planetary and imaging tube.
Because magnification is the telescope's 1500 mm focal length divided by the eyepiece focal length, a 25 mm eyepiece gives 60x here and a 10 mm eyepiece gives 150x. The highest useful magnification is the published 354x, 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.