Eyepiece and telescope pairing
Best eyepiece for the Orion SkyQuest XT4.5 Classic Dobsonian
Which eyepiece gets the most out of the Orion SkyQuest XT4.5 Classic Dobsonian, chosen by exit pupil rather than by guesswork.
- Aperture / focal length
- 114 mm / 900 mm (f/7.9)
- Deep-sky pick
- Celestron Omni 15mm Plossl: 60x, 1.9 mm exit pupil
- Low-power pick
- Celestron Omni 40mm Plossl: 22x, 5.07 mm exit pupil
- Focuser barrel
- 1.25 in (both eyepieces fit)
For deep-sky detail, the Celestron Omni 15mm Plossl is the pick of the eyepieces here: at 60x it lands near the 2 mm exit pupil where faint-object contrast peaks in the Orion SkyQuest XT4.5 Classic Dobsonian. For wide low-power sweeping, drop to the Celestron Omni 40mm Plossl at 22x.
An exit pupil near 2 mm is the classic sweet spot for teasing detail out of faint deep-sky objects, because it concentrates the light while keeping the image bright enough. In the Orion SkyQuest XT4.5 Classic Dobsonian the Celestron Omni 15mm Plossl lands there, at 60x with a 1.9 mm exit pupil and a 0.83 degree field.
For a low-power finder-and-framing view you want a wider exit pupil, around 5 mm. Here the Celestron Omni 40mm Plossl gives 22x, a 5.07 mm exit pupil and a 1.78 degree field, the widest true field of the eyepieces that fit this focuser.