Eyepiece and telescope pairing

Celestron Omni 32mm Plossl in the Sky-Watcher Skymax 127: magnification and field

What the Celestron Omni 32mm Plossl does in the Sky-Watcher Skymax 127, worked from the published focal lengths and apparent field.

Field of view

ring = 1 degrees true
dot = 2.6 mm exit pupil

Computed optics

Magnification
48x1540 mm / 32 mm
True field
1 degrees48 deg / 48x
Exit pupil
2.6 mm127 mm / 48x
Max useful mag
about 254x2x aperture
Barrel match
1.25 in eyepiece in a 2 in focuser
Fits

Good fit. In the Sky-Watcher Skymax 127 the Celestron Omni 32mm Plossl gives 48x with a 1 degree true field and a 2.6 mm exit pupil, inside the telescope's useful range.


Magnification is the telescope focal length divided by the eyepiece focal length: 1540 mm divided by 32 mm is 48x. The true field of view is the eyepiece's 48 degree apparent field divided by that magnification, 1 degrees.

The exit pupil, the width of the light beam leaving the eyepiece, is the aperture divided by the magnification, 127 mm over 48x, which is 2.6 mm. That makes this a medium-power general setting.