Celestron Ultima Edge 10mm — image 1
Celestron

Celestron Ultima Edge 10mm

A 10mm Celestron Ultima Edge: a medium-high-power eyepiece for planets, globular cores and small planetary nebulae, from a flat-field 65-degree eyepiece that stays sharp to the edge in fast scopes.

77/ 100
Polaris Score
Optical quality · Immersion · Comfort · Value
See the breakdown ↓
What it's for
Low power · wide fieldHigh power · narrow field

Medium-high power. At 10mm this is a medium-high-power eyepiece for planets, globular cores and small planetary nebulae; it is not meant for framing large deep-sky objects.

Apparent Field
60°
Barrel Size
1.25"
Eye Relief
16mm
Focal Length
10mm
From$109.95

Lowest in 90 daysLowest ever tracked

Price tracked by PolarisObserved 100 timesTracking since Jul 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.

60° apparent field

At 60°, you are aware of the field edge, like looking down a short, comfortable tube.
Try this eyepiece on your own scope in the Simulator →
01What it's good at

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

A genuinely flat field: sharp corner to corner, even in f/5 Newtonians.
Best at
✓A genuinely flat field: sharp corner to corner, even in f/5 Newtonians.
✓A genuinely flat field: sharp corner to corner, even in f/5 Newtonians.
✓At 10mm it lands squarely in medium-high power territory, exactly where planetary and lunar detail lives.
Trade-offs
!A 65-degree field, wider than a Plössl but short of a true ultra-wide.
!The lineup covers fewer focal lengths than the big modular ranges.
!Eyecup adjustment is basic.
02In your telescope

One eyepiece. A different job in every scope.

48× in a small refractor, 203× in a long SCT

An eyepiece has no magnification of its own — the telescope decides. The same eyepiece becomes 48× and 1.3° 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
1.3°
Exit pupil
1.8 mm
48× across a 1.3° field at a 1.8mm exit pupil, crisp medium power for galaxies, clusters and planetary nebulae.
8-inch Dobsonian
1200 mm · f/6
Magnification
120×
True field
30′
Exit pupil
1.7 mm
120× across a 30′ field at a 1.7mm exit pupil, crisp medium power for galaxies, clusters and planetary nebulae.
12-inch Dobsonian
1500 mm · f/5
Magnification
150×
True field
24′
Exit pupil
2.0 mm
150× across a 24′ field at a 2mm exit pupil, crisp medium power for galaxies, clusters and planetary nebulae.
8-inch SCT
2032 mm · f/10
Magnification
203×
True field
18′
Exit pupil
1.0 mm
203× across a 18′ field at a 1mm exit pupil, high power for planets, the Moon and tight doubles.
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.

10mm FL · 60° AFOV · 1.25"
Focal lengthHigh power
10mm
About 120x in an 8 inch f/5.9 Dobsonian and 203x in an 8 inch SCT. A dependable high power for planets, lunar detail and globular clusters that works on ordinary nights rather than only exceptional ones.
Apparent fieldModerate
60°
Sixty degrees is a comfortable middle ground: noticeably more open than a Plössl, without the outer-field demands an 82 degree design places on a fast telescope. That balance is what this range is built around.
Eye reliefComfortable
16mm
Sixteen millimetres is enough for relaxed viewing and workable with thin glasses, which is unusual at this focal length and makes long planetary sessions less tiring.
BarrelStandard
1.25"
Fits any focuser or diagonal, and the eyepiece is light enough not to disturb a Dobsonian's balance when swapped in.
OpticsFlat field
Fully multi-coated
The Ultima Edge design targets a flat, well corrected field rather than maximum width, so stars stay tight closer to the edge than most eyepieces at this price. That is the more useful choice in a fast Newtonian.
04What comes alive

The targets this eyepiece was born for.

Jupiter and its moons, Saturn, The Moon, M13 globular cluster, The Ring and Cat’s Eye…
Jupiter and its moonsComes alive
Jupiter and its moons
Belt detail with room to watch the Galilean moons shift.
SaturnComes alive
Saturn
Rings, the Cassini gap, and Titan in the same field.
The MoonExcellent
The Moon
A high-power tour of rilles, domes and crater chains.
M13 globular clusterExcellent
M13 globular cluster
The core starts to resolve into a spray of suns.
The Ring and Cat’s Eye nebulaeComes alive
The Ring and Cat’s Eye nebulae
Small planetary nebulae take real magnification well.
Excellent
Double stars
Clean, contrasty splits of colorful pairs.
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
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
06Build around it

What it pairs with.

The telescope · Pair it · Filter it
The telescope
What it goes into
Any 1.25-inch focuser
Fits essentially every telescope made.
Longer focal length scopes reward it
The higher the scope’s focal length, the more planetary scale you get from this eyepiece.
Pair it
What extends its range
A low-power finder eyepiece (~16mm)
Use the long eyepiece to locate and frame, then drop in this one for detail.
Filter it
What transforms the view
A neutral-density Moon filter
Tames the glare of a bright gibbous Moon at high power so detail returns.
07The Polaris Score

How it scores, and why.

77/100
77/ 100
Celestron Ultima Edge 10mm

Judged as a medium-high-power eyepiece for planets, globular cores and small planetary nebulae, it earns its score on a genuinely flat field: sharp corner to corner, even in f/5 newtonians. The comfortable eye relief lifts it further. It is honest about being a specialist, not an all-rounder.

Optical quality
80
Immersion
60
Comfort
84
Value
82

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.

Observers who want a medium-high-power eyepiece for planets, globular cores and small…
Buy it if you
✓Observers who want a medium-high-power eyepiece for planets, globular cores and small planetary nebulae.
✓Anyone who observes in eyeglasses; the eye relief here is long enough to see the whole field.
✓Observers who value on-axis contrast over a sprawling field.
Look elsewhere if you
!Anyone chasing the absolute widest field, who should look at a 100-degree eyepiece.
!Grab-and-go observers watching every gram, since this is not the lightest option.
!Anyone hoping to frame large nebulae; that is a job for a low-power eyepiece.
09The numbers

Full specifications.

4 measured and stated values
Optical
Focal Length10mm
Apparent Field60°
Comfort & handling
Eye Relief16mm
Fit & build
Barrel Size1.25"
Editor’s Take

Point it at a planet on a steady night and the case makes itself. This is where the Ultima Edge earns its keep.

— The Skynocular verdict