Eyepiece and telescope pairing
Celestron Omni 15mm Plossl in the Celestron NexStar 5SE: magnification and field
What the Celestron Omni 15mm Plossl does in the Celestron NexStar 5SE, worked from the published focal lengths and apparent field.
Field of view
ring = 0.6 degrees true
dot = 1.5 mm exit pupil
- Magnification
- 83x1250 mm / 15 mm
- True field
- 0.6 degrees50 deg / 83x
- Exit pupil
- 1.5 mm125 mm / 83x
- Max useful mag
- 295xpublished
Computed optics
- Barrel match
- 1.25 in eyepiece in a 1.25 in focuser
Good fit. In the Celestron NexStar 5SE the Celestron Omni 15mm Plossl gives 83x with a 0.6 degree true field and a 1.5 mm exit pupil, inside the telescope's useful range.
Magnification is the telescope focal length divided by the eyepiece focal length: 1250 mm divided by 15 mm is 83x. The true field of view is the eyepiece's 50 degree apparent field divided by that magnification, 0.6 degrees.
The exit pupil, the width of the light beam leaving the eyepiece, is the aperture divided by the magnification, 125 mm over 83x, which is 1.5 mm. That makes this a medium-power general setting.
The eyepiece to buy
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