Celestron X-Cel LX 5mm — image 1
Celestron

Celestron X-Cel LX 5mm

A 5mm Celestron X-Cel LX: a dedicated high-power eyepiece for planets, the Moon and tight double stars, from the reliable 60-degree all-rounder and the natural first upgrade from kit eyepieces.

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

High power. At 5mm this is a dedicated high-power eyepiece for planets, the Moon and tight double stars; it is not meant for framing large deep-sky objects.

Apparent Field
60°
Barrel Size
1.25"
Eye Relief
16mm
Focal Length
5mm
From$109.95

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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 constant 16mm of eye relief at every focal length, including the short planetary ones.
Best at
✓A constant 16mm of eye relief at every focal length, including the short planetary ones.
✓A constant 16mm of eye relief at every focal length, including the short planetary ones.
✓At 5mm it lands squarely in high power territory, exactly where planetary and lunar detail lives.
Trade-offs
!A 60-degree field is comfortable but not immersive next to an 82-degree eyepiece.
!Some lateral color on the Moon’s limb at the shortest focal lengths.
!Nothing here to excite an experienced observer chasing the widest fields.
02In your telescope

One eyepiece. A different job in every scope.

96× in a small refractor, 406× in a long SCT

An eyepiece has no magnification of its own — the telescope decides. The same eyepiece becomes 96× and 38′ of sky in a little refractor, or 406× 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
96×
True field
38′
Exit pupil
0.9 mm
96× across a 38′ field at a 0.9mm exit pupil, high power for planets, the Moon and tight doubles.
8-inch Dobsonian
1200 mm · f/6
Magnification
240×
True field
15′
Exit pupil
0.8 mm
240× across a 15′ field at a 0.8mm exit pupil, high power for planets, the Moon and tight doubles.
12-inch Dobsonian
1500 mm · f/5
Magnification
300×
True field
12′
Exit pupil
1.0 mm
300× across a 12′ field at a 1mm exit pupil, high power for planets, the Moon and tight doubles.
8-inch SCT
2032 mm · f/10
Magnification
406×
True field
9′
Exit pupil
0.5 mm
406× across a 9′ field at a 0.5mm exit pupil, very high power, worth it only on the steadiest nights.
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.

5mm FL · 60° AFOV · 1.25"
Focal lengthVery high power
5mm
About 240x in an 8 inch f/5.9 Dobsonian and 406x in an 8 inch SCT. In the Dobsonian this is a good steady-night planetary power; in the SCT it exceeds what most nights will support.
Apparent fieldModerate
60°
A moderate field that still meaningfully slows the drift of a planet across the view in an undriven telescope, compared with a 50 degree classic design.
Eye reliefComfortable
16mm
Generous for a 5 mm eyepiece, where the usual experience is pressing your eye against the glass. It makes high-power observing sustainable over a long session.
BarrelStandard
1.25"
Fits every telescope. The rubber grip is a genuine practical detail on cold nights when your fingers are numb and you are swapping eyepieces in the dark.
OpticsPlanetary value
Fully multi-coated
Full multi-coating on a six-element design gives good contrast and colour neutrality for the money. A simple orthoscopic will still edge it on absolute planetary contrast, at the cost of much tighter eye relief.
04What comes alive

The targets this eyepiece was born for.

Jupiter’s cloud belts, Saturn’s rings, Lunar craters at the terminator, Izar and tight…
Jupiter’s cloud beltsComes alive
Jupiter’s cloud belts
The two main belts and festoons resolve on steady nights.
Saturn’s ringsComes alive
Saturn’s rings
The Cassini Division opens up at this magnification.
Lunar craters at the terminatorExcellent
Lunar craters at the terminator
Crater walls and central peaks throw hard shadows.
Excellent
Izar and tight double stars
Splits pairs under an arcsecond apart when the air is calm.
Mars at oppositionExcellent
Mars at opposition
Polar cap and dark albedo markings when Mars is close.
The Ring Nebula (M57)Excellent
The Ring Nebula (M57)
Tightens the smoke ring and darkens the sky around it.
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
5 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 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 (~8mm)
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 X-Cel LX 5mm

Judged as a dedicated high-power eyepiece for planets, the Moon and tight double stars, it earns its score on a constant 16mm of eye relief at every focal length, including the short planetary ones. The comfortable eye relief lifts it further. It is honest about being a specialist, not an all-rounder.

Optical quality
78
Immersion
60
Comfort
84
Value
85

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 dedicated high-power eyepiece for planets, the Moon and tight double…
Buy it if you
✓Observers who want a dedicated high-power eyepiece for planets, the Moon and tight double stars.
✓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 Length5mm
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 X-Cel LX earns its keep.

— The Skynocular verdict
10Alternatives

For a different goal, start here.

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

Celestron X-Cel LX 9mm

The same optics with more true field, for framing larger objects and finding your way around.

→
More magnification

Celestron X-Cel LX 2.3mm

The same line at higher power, for planets and the smallest deep-sky detail.

→
Cross-shop

Explore Scientific 5.5mm 62°

A natural alternative at a nearby price point, if you want to compare field and feel before committing.

→