Optical reference

Celestron PowerSeeker 127EQ: aperture, focal length and eyepiece fit

What the Celestron PowerSeeker 127EQ measures, the magnification and true field each eyepiece produces in it, and the barrel, mount payload and camera adapter that fit.

Published specifications

Aperture
127 mm (5 in)
Focal length
1000 mm
Focal ratio
f/7.87
Optical design
Newtonian reflector (spherical primary, Bird-Jones)
Focuser / eyepiece barrel
1.25 in focuser
Mount
Manual German equatorial
Highest useful magnification (published)
300x

Eyepiece ladder

2 pairings

The PowerSeeker 127EQ is a 127 mm Bird-Jones Newtonian, where a corrector lens in the focuser lets a short tube claim a 1000 mm focal length. The bundled 4 mm eyepiece and 3x Barlow push magnifications far past what the optics resolve, so real detail comes at more modest powers.

Because magnification is the telescope's 1000 mm focal length divided by the eyepiece focal length, a 25 mm eyepiece gives 40x here and a 10 mm eyepiece gives 100x. The highest useful magnification is the published 300x, 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.

Match an eyepiece, mount or camera