Celestron C14 optical tube: 356 mm aperture, 3910 mm focal length, f/11, Schmidt-Cassegrain. The magnification, true field and exit pupil each eyepiece gives, and the barrel, mount and camera adapter that fit.

Updated 05 September 2026.

Optical reference

Celestron C14 optical tube: aperture, focal length and eyepiece fit

What the Celestron C14 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

Aperture
356 mm (14.02 in)
Focal length
3910 mm
Focal ratio
f/11
Optical design
Schmidt-Cassegrain
Focuser / eyepiece barrel
1.25 in visual back (SCT rear cell); a 2 in diagonal fits with an SCT-to-2 in adapter
Mount
Optical tube only (CGE Pro / heavy dovetail), no mount supplied
Highest useful magnification (published)
840x
Optical tube weight
45 lb

Eyepiece ladder

2 pairings

The C14 is the largest Schmidt-Cassegrain in the C-series, 356 mm of aperture at a 3910 mm focal length. It needs a heavy mount and gathers enough light for demanding deep-sky and high-resolution planetary work.

Because magnification is the telescope's 3910 mm focal length divided by the eyepiece focal length, a 25 mm eyepiece gives 156x here and a 10 mm eyepiece gives 391x. The highest useful magnification is the published 840x, beyond which the image dims and softens without showing more detail.

The focuser takes 2 in eyepieces, so long 2 in wide-field eyepieces such as the Omni 56 mm fit as well as 1.25 in ones.

Match an eyepiece, mount or camera

Questions and answers

What is the aperture of the Celestron C14 optical tube?

356 mm (14.02 in)

What is the focal length of the Celestron C14 optical tube?

3910 mm

What is the focal ratio of the Celestron C14 optical tube?

f/11

What is the optical design of the Celestron C14 optical tube?

Schmidt-Cassegrain