Celestron

Celestron Omni 40mm

A 40mm Celestron Omni Plössl: a wide-field, low-power eyepiece for the biggest objects and rich star fields, from a clean, honest 52-degree Plössl that does one job well for very little money.

74/ 100

Polaris Score

Performance · ease · portability · upgrade path

See the breakdown ↓

Apparent Field

43°

Barrel Size

1.25"

Eye Relief

28mm

Focal Length

40mm

From$52.95

Lowest in 90 days

Price tracked by PolarisObserved 53 timesTracking since Jul 2026

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Where to buy

Agena AstroProductsPartnerBest price$52.95→Astronomics$52.95→Starizona$52.95→High Point Scientific$52.95→

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01What it's good at

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

Best at

✓Inexpensive enough to build a whole starter set around.

✓Light and small; no strain on any focuser.

✓At 40mm it lands squarely in low power · wide field territory, exactly where wide star fields and large objects belong.

Trade-offs

!Short eye relief at the short focal lengths, uncomfortable below about 10mm.

!A 52-degree field feels narrow once you have looked through anything wider.

!Basic coatings and build compared with premium glass.

02The Polaris Score

How it scores, and why.

74/ 100

Celestron Omni 40mm

Performance

Ease of use

Portability

Upgrade potential

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

✓Observers who want a wide-field, low-power eyepiece for the biggest objects and rich star fields.

✓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 who has looked through a wide-field eyepiece and cannot go back to a 52-degree tunnel.

!Grab-and-go observers watching every gram, since this is not the lightest option.

!Planetary specialists who want the last ounce of high-power contrast from an orthoscopic.

05The numbers

Full specifications.

Optical

Focal Length40mm

Apparent Field43°

Comfort & handling

Eye Relief28mm

Fit & build

Barrel Size1.25"

06Alternatives

For a different goal, start here.

Wider, lower power

Celestron Omni Plössl 64mm

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

More magnification

Celestron Omni Plössl 24mm

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

Cross-shop

Celestron X-Cel LX

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

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