At a Glance
17.3mm
Focal Length
72°
Apparent FOV
20mm
Eye Relief
1.25"
Barrel Size
Score Breakdown
Overview
The Tele Vue Delos 17.3mm sits in a sweet spot for visual astronomy. At 17.3mm focal length, it delivers useful magnification across a wide range of telescope focal lengths, making it genuinely versatile for both planetary work and deep-sky observing. The 72-degree apparent field is wide enough to feel immersive without the edge distortion that plagues cheaper wide-field designs. Tele Vue's fully multi-coated optics keep contrast high, which matters most when you are trying to tease out detail in nebulae or track down faint galaxies.
The 20mm eye relief is a real practical advantage. Eyeglass wearers can actually use this eyepiece without pressing their glasses against the lens, and observers without glasses will find extended sessions genuinely comfortable. The 1.25-inch barrel fits the vast majority of telescopes, so compatibility is rarely a concern. At $438, this is not an impulse purchase.
But Tele Vue eyepieces hold their resale value well, and the Delos line is consistently praised by experienced observers for optical quality that holds up under critical use. If you are building a long-term eyepiece collection, this one earns its place.
Key Features
- 72-degree apparent field provides wide, immersive views without significant edge distortion
- 20mm eye relief makes this one of the more comfortable options for eyeglass wearers
- Fully multi-coated optics support high contrast, useful for both planetary detail and faint deep-sky objects
- 17.3mm focal length works well across a broad range of telescope types and focal ratios
- Standard 1.25-inch barrel ensures compatibility with nearly any focuser
- Tele Vue's build quality and reputation mean strong long-term durability and resale value
- A strong investment for observers who want one reliable eyepiece that handles varied targets well
Specifications
| Focal Length | 17.3mm |
| Apparent FOV | 72° |
| Eye Relief | 20mm |
| Barrel Size | 1.25" |
| Design | Modified Nagler |
| Elements/Groups | 8/4 |
| Series | Delos |
| Coating | Fully Multi-Coated |
| Waterproof | No |
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Amazon Reviews
You will love the clarity of the stars and everything else you view with the Delos series eyepieces. The views are just amazing. The eye relief is perfect and the adjustable barrel makes for an unbeatable eyepiece. Once you buy and use one Delos, you will want the rest.
This is my first eyepiece purchase, my other eyepieces are the 25mm and 10mm ones that came with my scope. WHAT A DIFFERENCE! This thing is so comfortable to use and everything looks great all the way to the edge. I have since picked up a 35mm panoptic and plan on filling in my collection with the 4...
This is a truly exceptional eyepiece: views are extremely sharp for planetary and globular clusters. Using it with my 20" dob, I saw details that I never saw with any other eyepiece or telescope. Great, period.
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