Tele Vue

Tele Vue Delos 10mm

The most comfortable way to see a planet sharply. A tack-sharp 72-degree field with a full 20 mm of eye relief, the medium-high-power eyepiece you can look into for an hour without a single squint.

91/ 100

Polaris Score

Optical quality · Immersion · Comfort · Value

See the breakdown ↓

What it's for

Low power · wide fieldHigh power · narrow field

A medium-to-high-power eyepiece for detail work: planets, globulars, galaxies and planetary nebulae at a comfortable scale. Wide enough to be immersive, but this is a sharpshooter, not a rich-field sweeper.

Apparent Field

72°

Barrel Size

1.25"

Eye Relief

20mm

Focal Length

10mm

From$438

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Price tracked by PolarisObserved 73 timesTracking since Jun 2026

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The spacewalk

You don’t look at a field.
You look into the sky.

Every number on the spec sheet matters less than one feeling: how much sky wraps around your eye. Widen the apparent field and watch the black edge of the eyepiece slip away.

72° apparent field

At 72°, the black rim sits out at the corner of your attention rather than in front of you.

See this field in your own scope in the Simulator →

01What it's good at

What it's best at — and the trade-offs.

Best at

✓A full 20 mm of eye relief at 10 mm focal length, which almost no competitor matches, making long high-power sessions effortless.

✓Pinpoint stars and high contrast right to the edge of the 72-degree field, even at f/5.

✓One of the sharpest, most neutral planetary and lunar views available without stepping up to exotic glass.

Trade-offs

!Expensive for a single focal length, and you'll want two or three to cover the range.

!Heavy; a full kilo of eyepieces will rebalance a light Dob or refractor.

!The 72-degree field is generous but not the ultra-wide immersion of an 82 or 100-degree design.

02In your telescope

One eyepiece. A different job in every scope.

An eyepiece has no magnification of its own — the telescope decides. The same eyepiece becomes 48× and 1.5° of sky in a little refractor, or 203× and a tight frame in a long SCT. Here’s what it does across common scopes.

Small apo refractor

480 mm · f/5.5

Magnification

48×

True field

1.5°

Exit pupil

1.8 mm

A wide, comfortable 48x and 1.5 degrees in the little refractor; more magnification than you'd think, with the whole field usably sharp.

8-inch Dobsonian

1200 mm · f/6

Magnification

120×

True field

36′

Exit pupil

1.7 mm

120x and a bright 1.7 mm exit pupil in the 8-inch Dob, the sweet spot for globulars, galaxies and the brighter planetary nebulae.

12-inch Dobsonian

1500 mm · f/5

Magnification

150×

True field

29′

Exit pupil

2.0 mm

150x in the big Dob with pinpoint stars to the edge; steady nights reward this scale on Jupiter and Saturn.

8-inch SCT

2032 mm · f/10

Magnification

203×

True field

21′

Exit pupil

1.0 mm

203x out of the long SCT with a 1 mm exit pupil, high-power lunar and planetary detail rendered with easy, relaxed viewing.

Exit pupil is how wide the beam of light leaving the eyepiece is. Around 5–6 mm is bright and immersive under dark skies; push much past 6 mm and you waste light, and under light pollution a smaller exit pupil shows more contrast.

02In plain English

The numbers, in plain English.

20 mm eye reliefThe signature spec

Effortless

You sit back from the lens and observe with glasses on, at a focal length where most eyepieces force your eye against the glass.

72° apparent fieldWide, not ultra-wide

Immersive

Enough field that a planet has room to drift and deep-sky objects sit in space, without the size and cost of a 100-degree eyepiece.

Edge sharpnessHolds at f/5

Pinpoint

Stars stay tight and neutral to the field stop even in fast scopes, the hard part of eyepiece design, solved.

~350 gRebalances light scopes

Substantial

You'll feel it in a small refractor or grab-and-go Dob; a fair trade for the view and comfort.

03What comes alive

The targets this eyepiece was born for.

Comes alive

Jupiter

Belts, festoons and the Great Red Spot in a sharp, high-contrast, and above all comfortable high-power view.

Comes alive

Saturn

The Cassini Division and banded disc hold steady, framed with room to watch it drift.

Comes alive

The Moon

Crater walls and rilles at the terminator, with the eye relief to scan for long stretches without fatigue.

Excellent

Ring Nebula

Small but bright; this focal length lifts it from a smoke ring to a structured, three-dimensional shell.

Excellent

M13 Hercules Cluster

Resolves cleanly into thousands of stars in an 8-inch and up, set in a sharp, dark field.

Excellent

Double stars

Tight pairs split cleanly thanks to the high contrast and edge-to-edge sharpness.

04Role in a collection

Where it sits in your eyepiece case.

A good eyepiece collection isn’t a pile of glass — it’s two or three focal lengths that hand off from wide to tight. This is the anchor at the bottom of the ladder: the one you find and frame with. You buy it once, and it stays your low-power eyepiece for life.

32 mm

Low power · wide field

Find, frame and sweep. Your widest true field and the lowest useful magnification, the eyepiece you reach for first.

Veil Nebula · Pleiades · Milky Way star clouds

10 mmThis one

Medium power · the workhorse

Where most deep-sky objects look their best, galaxies, globulars and planetary nebulae at a comfortable scale.

M13 · Ring Nebula · most galaxies

7 mm

High power · detail

Planets, the Moon at the terminator, tight double stars and the smallest planetary nebulae. Steady-air nights only.

Jupiter · Saturn · lunar craters

04Build around it

What it pairs with.

The telescope

What it goes into

Any scope, fast or slow

Its edge correction holds even at f/5, so it flatters Newtonians and refractors alike

8-inch and up for deep sky

Aperture turns the high power into resolved globulars and structured nebulae

Long SCT for planets

High native magnification plus this eyepiece's comfort is a superb planetary pairing

Pair it

What extends its range

A wide-field 2" eyepiece

The find-and-frame partner; you locate wide, then drop in the Delos to zoom

Another Delos or two

Parfocal within the line, so you barely touch the focuser swapping between them

Filter it

What transforms the view

Planetary / colour filters

The high contrast is a good base for teasing out belt and polar detail

OIII on planetary nebulae

At this focal length the Ring and similar shells take a filter well

02The Polaris Score

How it scores, and why.

91/ 100

Tele Vue Delos 10mm

Judged on delivering a sharp, high-contrast, genuinely comfortable medium-to-high-power view, it is close to flawless in any scope, fast or slow. The only real marks against it are price and weight, never the view itself.

Optical quality

Immersion

Comfort

Value

Polaris weighs how well the eyepiece does the job it was designed for — optics, immersion, comfort and value — never list price or brand.

03Who it's for

An honest fit check.

Buy it if you

✓You want planets, the Moon and small deep-sky objects rendered as sharply as your scope can manage, with zero eye strain.

✓You wear glasses, or simply hate pressing your eye into a tiny lens; the 20 mm of eye relief is transformative at this focal length.

✓You own a fast scope and want an eyepiece that stays pin-sharp to the edge without a coma corrector doing all the work.

✓You are building a buy-once eyepiece case and want the medium-high-power slot filled for good.

Look elsewhere if you

!You want the widest possible true field for sweeping; a long-focal-length wide-angle does that job, not this.

!You are on a tight budget, where a Celestron X-Cel or Explore Scientific gives most of the view for a quarter of the price.

!You need it to stay light; at over 350 grams it can rebalance a small scope.

!You already observe happily with short eye relief and won't pay a premium purely for comfort.

05The numbers

Full specifications.

Optical

Focal Length10mm

Apparent Field72°

Comfort & handling

Eye Relief20mm

Fit & build

Barrel Size1.25"

Editor’s Take

The Delos took the one thing Tele Vue's legendary eyepieces asked you to give up, comfortable eye relief at high power, and simply gave it back. Once you've spent a night behind one, cramped short-focal-length eyepieces start to feel like a compromise you no longer have to make.

— The Skynocular verdict

06Alternatives

For a different goal, start here.

The rival

Pentax XW 10mm

The other 20 mm-eye-relief high-power reference; weather-sealed, 70 degrees, and the classic head-to-head with the Delos.

One step wider

Tele Vue Delos 14mm

The same eyepiece a notch lower in power, for a touch more field and a larger exit pupil.

→Budget alternative

Celestron X-Cel LX 9mm

Most of the comfort and a good sharp view for a quarter of the price, if the Delos is a stretch.

→

Tele Vue Delos 10mm

You don’t look at a field.You look into the sky.

What it's best at — and the trade-offs.

One eyepiece. A different job in every scope.

The numbers, in plain English.

The targets this eyepiece was born for.

Where it sits in your eyepiece case.

What it pairs with.

How it scores, and why.

An honest fit check.

Full specifications.

For a different goal, start here.

You don’t look at a field.
You look into the sky.