Delos 8mm — image 1
Tele Vue

Delos 8mm

The Delos 8mm delivers high-power planetary and lunar views with a wide 72-degree field and a luxurious 20mm of eye relief. It is the eyepiece for observers who want serious magnification without the eye strain that usually comes with it.

91/ 100
Polaris Score
Optical quality · Immersion · Comfort · Value
See the breakdown ↓
What it's for
Low power · wide fieldHigh power · narrow field

A high-power field for planets, the Moon, double stars and globular cores, delivered with unusual comfort. It is not a wide-field deep-sky eyepiece; at 8mm the true field is narrow by design.

Apparent Field
72°
Barrel Size
1.25"
Eye Relief
20mm
Focal Length
8mm
From$438

Lowest in 90 days

Price tracked by PolarisObserved 55 timesTracking since Aug 2026

Try in simulator →
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.
Try this eyepiece on your own scope in the Simulator →
01What it's good at

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

20mm of eye relief across a 72-degree field is best-in-class comfort at high power, transforming long planetary sessions.
Best at
✓20mm of eye relief across a 72-degree field is best-in-class comfort at high power, transforming long planetary sessions.
✓The view is sharp and high-contrast to the edge, holding fine planetary and lunar detail steadily.
✓The adjustable eyecup lets you dial in the exact position for glasses or bare eye, so the full field is always usable.
Trade-offs
!It is noticeably heavier than an orthoscopic or Plössl of the same focal length, which matters for balance on small scopes.
!72 degrees is wide for a planetary eyepiece but modest next to the 82- and 100-degree ultra-wides.
!It is a premium-priced eyepiece for a job a simpler, cheaper design can also do, if you accept less comfort.
02In your telescope

One eyepiece. A different job in every scope.

60× in a small refractor, 254× in a long SCT

An eyepiece has no magnification of its own — the telescope decides. The same eyepiece becomes 60× and 1.2° of sky in a little refractor, or 254× 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
60×
True field
1.2°
Exit pupil
1.5 mm
In a short apo it gives a comfortable 60x over 1.2 degrees, enough for lunar detail, the brighter planets and tight doubles with room around them.
8-inch Dobsonian
1200 mm · f/6
Magnification
150×
True field
29′
Exit pupil
1.3 mm
In an 8-inch f/6 Dob this is the planetary workhorse, 150x on Jupiter's belts and Saturn's rings, held in comfort across a half-degree field.
12-inch Dobsonian
1500 mm · f/5
Magnification
188×
True field
23′
Exit pupil
1.6 mm
In a fast 12-inch it reaches 187x for globular cores and planetary detail, the wide field and long eye relief keeping the view easy to hold.
8-inch SCT
2032 mm · f/10
Magnification
254×
True field
17′
Exit pupil
0.8 mm
In an f/10 SCT it pushes to 254x on a small 0.8mm exit pupil, high-power planetary and double-star territory on nights of good seeing.
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.
03In plain English

The numbers, in plain English.

8mm FL · 72° AFOV · 1.25"
Eye reliefGenerous
20 mm
The signature feature: high power without pressing your eye to the lens, comfortable for an hour on the planets, glasses on or off.
Focal lengthHigh power
8 mm
Delivers the magnification for planetary detail, lunar craters, tight doubles and globular cores in most scopes.
Apparent fieldWide
72°
Wide enough that a planet drifts slowly across the field on an undriven mount, giving you time to study it.
Exit pupil (typical)Small
1.0-1.6 mm
A small exit pupil that darkens the sky and lifts planetary contrast, ideal for high-power work.
BarrelStandard
1.25"
Fits any focuser and stays reasonably compact for its performance, unlike the 2-inch ultra-wides.
04What comes alive

The targets this eyepiece was born for.

Jupiter, Saturn, The Moon, Mars, Globular clusters (M13), Double stars (Albireo)
JupiterComes alive
Jupiter
Belt detail and the Great Red Spot held steady in comfort at high power.
SaturnComes alive
Saturn
The rings, the Cassini division and the planet's shadow, easy to study over long minutes.
The MoonComes alive
The Moon
Crater walls and rilles at high power, with eye relief that makes lingering effortless.
MarsExcellent
Mars
At opposition, the polar cap and dark markings when the seeing allows.
Globular clusters (M13)Excellent
Globular clusters (M13)
High power begins to resolve the core into individual stars.
Excellent
Double stars (Albireo)
Tight pairs split cleanly, with color and comfortable viewing.
05Role in a collection

Where it sits in your eyepiece case.

Where it sits across 3 focal lengths

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
13 mm
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
8 mmThis one
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
06Build around it

What it pairs with.

The telescope · Pair it · Filter it
The telescope
What it goes into
Any scope with good optics
Refractor, SCT or Dob; high power rewards a well-collimated, cooled scope.
A steady mount
At high power a stable mount or a driven Dob makes the view much easier to study.
Pair it
What extends its range
Delos 6mm
Delos 6mm
Steps up to higher power for the planets on the best nights.
Delos 12mm or 14mm
Drops to medium power for globulars and smaller galaxies.
Filter it
What transforms the view
Neutral density or polarizing filter
Tames the glare of the full Moon for comfortable high-power detail.
Planetary color filters
A light blue or red filter can lift specific detail on Jupiter and Mars.
07The Polaris Score

How it scores, and why.

91/100
91/ 100
Delos 8mm

Judged as a comfortable high-power eyepiece it is nearly the reference: sharp, high-contrast, with 20mm of eye relief that makes long planetary sessions effortless, glasses on or off. It gives up only a little immersion to the 82- and 100-degree ultra-wides, which is not what this eyepiece is for.

Optical quality
93
Immersion
83
Comfort
95
Value
80

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

08Who it's for

An honest fit check.

Planetary, lunar and double-star observers who want high magnification and refuse to trade…
Buy it if you
✓Planetary, lunar and double-star observers who want high magnification and refuse to trade away comfort to get it.
✓Eyeglass wearers, who finally get a high-power eyepiece with 20mm of eye relief and a full 72-degree field.
✓Anyone who has found short focal length eyepieces uncomfortable and given up on long high-power sessions.
✓Observers assembling a premium kit who want one high-power eyepiece that is a pleasure to use for an entire evening.
Look elsewhere if you
!Wide-field deep-sky observers: at 8mm the true field is narrow, and this eyepiece is not meant to frame large objects.
!Ultralight and travel setups, where a small orthoscopic or Plössl weighs a fraction as much.
!Budget buyers, who can get sharp high-power views from a good Plössl for far less, if they accept short eye relief.
!Observers who genuinely do not mind short eye relief, for whom the Delos comfort premium solves a problem they do not have.
09The numbers

Full specifications.

4 measured and stated values
Optical
Focal Length8mm
Apparent Field72°
Comfort & handling
Eye Relief20mm
Fit & build
Barrel Size1.25"
Editor’s Take

High power is where most eyepieces get uncomfortable, your eye jammed against a tiny lens and the field reduced to a keyhole. The Delos rewrites that: 20mm of eye relief and a 72-degree field let you settle in and study Jupiter or the Moon for an hour without fatigue. Once you have observed the planets in comfort, going back is hard.

— The Skynocular verdict
10Alternatives

For a different goal, start here.

3 alternatives, each mapped to the goal it wins at
Higher power

Delos 6mm

The same comfort pushed to more magnification for the planets on nights of excellent seeing.

→
Lower power

Delos 10mm

A more forgiving magnification for average seeing and smaller scopes, with the same 20mm eye relief.

→
Comfort competitor

Pentax XW 7mm

A rival premium eyepiece with similar long eye relief and a slightly wider field.

→
Community

Used in these setups.

Real builds from the community that include this product.

Deep Sky Explorer

Featured

A big-aperture visual Dobsonian paired with premium wide-field eyepieces. Ten inches of aperture pulls in faint galaxies and globular clusters, and the Ethos/Delos eyepieces deliver those photons with immersive, edge-to-edge sharpness under dark skies.