At a Glance
40mm
Focal Length
50°
Apparent FOV
28mm
Eye Relief
1.25"
Barrel Size
Score Breakdown
Overview
The SVBONY 40mm Plossl is a straightforward, budget-friendly eyepiece that fills a useful role in any starter kit. At 40mm focal length, it delivers your lowest magnification option on most telescopes, which means wider fields of view and brighter images. That makes it genuinely well-suited for sweeping across the Moon, framing open clusters like the Pleiades or the Beehive, and picking out large, diffuse nebulae such as the Orion Nebula or Andromeda Galaxy.
The 40-degree apparent field of view is on the narrower side compared to premium wide-angle designs, so do not expect the immersive "spacewalk" effect of a 68 or 82-degree eyepiece. However, for the price, the fully multi-coated optics deliver respectable contrast and color accuracy. Planetary detail will be limited primarily by your telescope and seeing conditions, not this eyepiece.
The all-metal barrel, foldable rubber eye guard, and included plastic case make this feel more durable than the price suggests. The M28.5 filter thread accepts standard 1.25-inch filters, adding useful versatility. With over 1,000 Amazon reviews averaging 4.6 out of 5, it has a solid real-world track record for beginners.
Key Features
- 40mm focal length provides your widest, lowest-magnification view for a given telescope, ideal for large targets
- Fully multi-coated 4-element optics improve light transmission and reduce glare compared to single-coated alternatives
- Foldable rubber eye guard accommodates eyeglass wearers comfortably and blocks stray light
- Standard 1.25-inch barrel fits the vast majority of beginner and mid-range telescopes
- M28.5 filter thread allows direct attachment of 1.25-inch filters without additional adapters
- All-metal construction and included plastic storage case add durability and portability at a budget price point
- 40-degree apparent field of view is functional but narrower than premium wide-angle eyepieces, worth noting before buying
Specifications
| Focal Length | 40mm |
| Apparent FOV | 50° |
| Eye Relief | 28mm |
| Barrel Size | 1.25" |
| Design | Plossl |
| Elements/Groups | 4/2 |
| Series | Plossl |
| Coating | Fully Multi-Coated |
| Waterproof | No |
Popular Telescopes for This Eyepiece
Celestron EdgeHD 800 OTA
51x / 4.0mm exit pupil / Schmidt-Cassegrain
Celestron NexStar 8SE
51x / 4.0mm exit pupil / Schmidt-Cassegrain
Celestron CGEM II 1100
70x / 4.0mm exit pupil / Schmidt-Cassegrain
Celestron CPC Deluxe 800 HD
51x / 4.0mm exit pupil
Amazon Reviews
nice and clear. wider angle makes a clearer image
I didn't pay very much for this eyepiece, so I was really surprised to see how good it was for the money. I bought it primarily for stargazing. I wanted to bring the power on my 70mm Celestron spotting scope down to 10X (the longest focal length stock eyepiece it came with was 20mm, or 20X). This ey...
Great value! But beware, this focal length won't work well for fast scopes with large obscurations! Optical reality, not the fault of the eyepiece. For example - a 6" F4 Newtonian. The magnification will be 15X and the exit pupil diameter 10mm! A typical eye pupil is only 6mm, so you get the center ...
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