Celestron SkyMaster 25X100 Astro Binoculars
- Size
- 25x100
- Protection
- Water resistant; not waterproof; not nitrogen filled
Maker specs: Celestron SkyMaster 25x100
Astronomy binoculars
Compare 3 astronomy binoculars for stargazing, from a 10x50 you can hold in your hands to two 25x100 giants that need a tripod. Choose by magnification, objective size and exit pupil, then by weight and how you will mount the pair.
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This is a small list: one pair you can hold in your hands and two big pairs that need a solid tripod. If you want something in between, such as a 15x70 or 20x80, read our 20x80 guide further down and check the maker's page for weight and tripod fitting.
- 3 models
- 3 with our score out of 10
- 2 with maker-listed specs
Best binoculars for astronomy and stargazing: our picks
Nikon ACULON A211
- Size
- 10x50
- Eye relief
- 11.8mm
- Field of view
- 341 ft. at 1000 yds (6.5° real)
Maker specs: Nikon ACULON A211 10x50
Our astronomy guides
The full lists these picks come from, with our notes on every pair.
Compare astronomy binoculars
Scroll sideways to see every comparison field and Shopping action.
| Model | Magnification | Objective (mm) | Eye relief | Field of view | Maker’s model | Shopping action |
|---|---|---|---|---|---|---|
| Celestron SkyMaster 25X100 Astro Binoculars | 25x | 100 | Celestron SkyMaster 25x100 | |||
| Nikon ACULON A211 | 10x | 50 | 11.8mm | 341 ft. at 1000 yds (6.5° real) | Nikon ACULON A211 10x50 |
One model without a maker’s figure record is listed in the picks above.
Astronomy binocular questions
Can you see Saturn's rings with binoculars?
Only as a hint. NASA says binoculars may show the rings as small "ears" beside the planet, depending on the pair, and that even a small telescope shows more ring detail (NASA).
If seeing the rings clearly is your main goal, a small telescope is the better buy.
Can you see Jupiter's moons with binoculars?
Yes. NASA says Jupiter's four largest moons are easily visible through modest binoculars as a series of pinpoints of light around the planet (NASA).
Rest the binoculars on something solid or use a tripod so the points hold still.
What magnification is best for stargazing?
Start between 7x and 10x. NASA's Night Sky Network suggests 7x35 to 10x50 for a first pair and advises against much more power than 10x50 at first, because larger, more powerful pairs are often heavier and harder to hold steady (NASA).
Go to 15x or more only with a tripod. Our 10x42 vs 10x50 guide explains why 10x50 is often preferred for stargazing.
Do I need a tripod for astronomy binoculars?
Yes for the two 25x100 pairs in this list. Celestron treats a tripod as essential at 15x and above, for 70 mm to 100 mm objectives, and for astronomy binoculars weighing 3 to 9 lb (Celestron). Celestron lists its SkyMaster 25x100 at 140 oz (8.75 lb).
The Nikon Aculon A211 10x50, 31.7 oz on Nikon's sheet, works without a tripod, though one steadies long sessions. See our tripod guide.
Should I choose 7x50, 10x50 or 20x80 for stargazing?
Choose 10x50 for a first pair you hold in your hands, 7x50 for the brightest view without a tripod, and 20x80 only if you will use a tripod. Divide the objective by the magnification for the exit pupil: about 7.1 mm for 7x50, 5 mm for 10x50 and 4 mm for 20x80.
Celestron puts a fully dark-adapted pupil at 5 mm to 7 mm, with 7 mm the maximum for the human eye (Celestron). Our 20x80 guide covers the big size.
Should a beginner buy binoculars or a telescope?
Buy binoculars first unless planets are your main interest. NASA calls binoculars an excellent first instrument because they are easy to use and more versatile than most telescopes, and lists the Moon, the Pleiades and Jupiter's moons among their targets (NASA).
A telescope is the better tool once you want detail such as Saturn's rings.
How to choose binoculars for stargazing
Choose a size by how you will observe
Decide first whether you will hold the binoculars or mount them, because that settles the size more than the target does. NASA's suggested starting range of 7x35 to 10x50 covers pairs you can hold; Celestron puts 15x and larger on a tripod.
| Size | Suits | Trade-off |
|---|---|---|
| 7x50 | Brightest view in the hand | Less magnification on the Moon |
| 10x50 | First pair, in the hand or braced | Harder to hold still than 7x |
| 20x80 | Tripod sessions | Heavy; 4 mm exit pupil |
| 25x100 | Tripod only, like the two giants here | Very heavy; 4 mm exit pupil |
Check the eye relief if you observe in glasses
Look for at least 15 mm of eye relief if you keep your glasses on. Celestron says eye relief should be at least 10 mm, that 15 mm gives the best comfort and that glasses wearers may need more. Nikon lists 11.8 mm for the Aculon A211 10x50, so try it with your glasses on before you commit.
Plan the tripod before you buy a giant pair
A 25x100 needs a sturdy tripod and a way to fix the binoculars to it. Celestron lists an integrated tripod adapter rod on the SkyMaster 25x100, and our tripod guide compares mounts.
We do not have the maker's figures for the Orion Giant View 25x100, so check its product page for the mount fitting and weight.
Keep the big Celestron dry
Treat the SkyMaster 25x100 as a dry-weather instrument. Celestron rates it water resistant, not waterproof, and it is not nitrogen filled.
Never aim binoculars at the Sun
Keep the Sun out of view at all times, including at sunset. NASA warns that viewing any part of the bright Sun through binoculars without a special-purpose solar filter over the front will instantly cause severe eye injury.
Sizes of the listed astronomy binoculars
The table counts the listed models by size with each size's exit pupil, so you can see which pair you can hold and which two need a tripod.
| Size | Models | Exit pupil, calculated |
|---|---|---|
| 10x50 | 1 | 5.0 mm |
| 25x100 | 1 | 4.0 mm |
Guides on what you can see
Our guide to Andromeda with 10x50 binoculars explains how the galaxy shows as a faint, misty patch under dark skies, and our 20x80 guide covers what a big pair adds.
Guides on choosing a size
Compare 10x50 and 20x50 for magnification against steadiness, or read what 7x50 binoculars are used for if you want one pair for the sky and the water.