At a Glance
31mm
Focal Length
82°
Apparent FOV
18mm
Eye Relief
2"
Barrel Size
Score Breakdown
Overview
The Celestron Luminos 31mm is a low-power, wide-field eyepiece designed to give you sweeping 82-degree views of the night sky. At 31mm, it excels at finding deep-sky objects, framing large targets like open clusters, nebulae, and the Milky Way, and giving your observing sessions a satisfying sense of scale. The six or seven optical elements, depending on the model, are fully multi-coated, which helps deliver good contrast and light transmission rather than washing out faint detail.
One genuinely useful feature is that all six Luminos eyepieces are parfocal with each other, meaning you can swap between focal lengths during a session without hunting for focus each time. That is a real convenience when you are moving from a wide-field view to higher magnification. The rubber grip and retractable eyecup are practical touches, especially for observers who work in cold conditions or wear gloves.
The threaded barrel accepts standard filters, which is worth noting for observers interested in light pollution or nebula filters. At $299, it sits in the mid-range premium tier. It is a serious eyepiece, though beginners should consider whether a full Luminos set fits their budget before committing.
Key Features
- 82-degree apparent field of view provides immersive, wide-field views ideal for low-power sweeping
- Fully multi-coated optics improve contrast and light throughput for cleaner views of faint objects
- Parfocal with all other Luminos eyepieces, reducing refocusing time when changing magnifications
- Threaded barrel accepts standard filters, useful for light pollution or nebula filter applications
- Retractable eyecup accommodates both eyeglass and non-eyeglass wearers comfortably
- Rubber grip and anodized aluminum barrel offer solid handling in cold or wet conditions
- Backed by a two-year US warranty with access to Celestron's domestic support team
Specifications
| Focal Length | 31mm |
| Apparent FOV | 82° |
| Eye Relief | 18mm |
| Barrel Size | 2" |
| Design | Modified Nagler |
| Elements/Groups | 7/4 |
| Series | Luminos |
| Coating | Fully Multi-Coated |
| Waterproof | No |
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Amazon Reviews
What can you say about Luminos eyepieces? First impression, they are big and heavy. Lots of glass and metal that could put you over the limit on your mount if you are already close, but so worth the view! I now own the 31mm, 23mm, 19mm, and 15mm Luminos eyepieces. For the money they are a great valu...
Really a fantastic eyepiece. Going from the stock, 1.25" EPs to this was very cool. This thing is as big as -- and solid as -- a grenade! Make sure you balance your OTA with it on before you use it. Best with a quality diagonal, of course. (I use a Celestron, Dielectric Star 2" on a C9.25 SCT.) Very...
The build quality is excellent. It’s heavier than I expected, but that’s a testament to its sturdy anodized aluminum construction. The rubber grip is a nice touch, especially when observing in colder weather. I also appreciate the retractable eyecup, although I rarely use it fully extended.
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