Eyepiece and telescope pairing

Celestron Omni 12mm Plossl in the Celestron NexStar 6SE: magnification and field

What the Celestron Omni 12mm Plossl does in the Celestron NexStar 6SE, worked from the published focal lengths and apparent field.

Field of view

ring = 0.4 degrees true
dot = 1.2 mm exit pupil

Computed optics

Magnification
125x1500 mm / 12 mm
True field
0.4 degrees50 deg / 125x
Exit pupil
1.2 mm150 mm / 125x
Max useful mag
354xpublished
Barrel match
1.25 in eyepiece in a 2 in focuser
Fits

Good fit. In the Celestron NexStar 6SE the Celestron Omni 12mm Plossl gives 125x with a 0.4 degree true field and a 1.2 mm exit pupil, inside the telescope's useful range.


Magnification is the telescope focal length divided by the eyepiece focal length: 1500 mm divided by 12 mm is 125x. The true field of view is the eyepiece's 50 degree apparent field divided by that magnification, 0.4 degrees.

The exit pupil, the width of the light beam leaving the eyepiece, is the aperture divided by the magnification, 150 mm over 125x, which is 1.2 mm. That makes this a high-power lunar, planetary and double-star setting.