Eyepiece and telescope pairing

Celestron Omni 32mm Plossl in the Celestron StarSense Explorer 8-inch Dobsonian: magnification and field

What the Celestron Omni 32mm Plossl does in the Celestron StarSense Explorer 8-inch Dobsonian, worked from the published focal lengths and apparent field.

Field of view

ring = 1.28 degrees true
dot = 5.4 mm exit pupil

Computed optics

Magnification
38x1200 mm / 32 mm
True field
1.28 degrees48 deg / 38x
Exit pupil
5.4 mm203 mm / 38x
Max useful mag
480xpublished
Barrel match
1.25 in eyepiece in a 2 in focuser
Fits

Good fit. In the Celestron StarSense Explorer 8-inch Dobsonian the Celestron Omni 32mm Plossl gives 38x with a 1.28 degree true field and a 5.4 mm exit pupil, inside the telescope's useful range.


Magnification is the telescope focal length divided by the eyepiece focal length: 1200 mm divided by 32 mm is 38x. The true field of view is the eyepiece's 48 degree apparent field divided by that magnification, 1.28 degrees.

The exit pupil, the width of the light beam leaving the eyepiece, is the aperture divided by the magnification, 203 mm over 38x, which is 5.4 mm. That makes this a low-power, wide-field and deep-sky setting.