Eyepiece and telescope pairing

Celestron Omni 56mm Plossl in the Celestron NexStar 8SE: magnification and field

What the Celestron Omni 56mm Plossl does in the Celestron NexStar 8SE, worked from the published focal lengths and apparent field.

Field of view

ring = 1.3 degrees true
dot = 5.6 mm exit pupil

Computed optics

Magnification
36x2032 mm / 56 mm
True field
1.3 degrees47 deg / 36x
Exit pupil
5.6 mm203 mm / 36x
Max useful mag
480xpublished
Barrel match
2 in eyepiece in a 2 in focuser
Fits

Good fit. In the Celestron NexStar 8SE the Celestron Omni 56mm Plossl gives 36x with a 1.3 degree true field and a 5.6 mm exit pupil, inside the telescope's useful range.


Magnification is the telescope focal length divided by the eyepiece focal length: 2032 mm divided by 56 mm is 36x. The true field of view is the eyepiece's 47 degree apparent field divided by that magnification, 1.3 degrees.

The exit pupil, the width of the light beam leaving the eyepiece, is the aperture divided by the magnification, 203 mm over 36x, which is 5.6 mm. That makes this a low-power, wide-field and deep-sky setting.