The Celestron SkyMaster 25×100 combines 25× magnification with 100 mm objective lenses, but its 3,969 g (140 oz) weight makes tripod-supported viewing central to the decision. It is a candidate for astronomy and long-distance terrestrial viewing if you can provide a sturdy, compatible mount; it is not a practical handheld binocular for extended observing.
What the SkyMaster 25×100 is designed to do
Celestron positions item 71017 for astronomy and long-range land viewing. Its 100 mm objectives and 25× magnification are the headline specifications, while the 3° angular field gives a relatively narrow view compared with lower-power binoculars. The maker lists multi-coated optics and BaK-4 prism glass; those are manufacturer specifications, not independent laboratory measurements. Celestron’s product listing also includes an individual-eyepiece focus system.
One review excerpt reproduced on Celestron’s page, labeled “Astronomy Now Review – July 2021 Edition,” says: “The SkyMaster 25×100 proves that a well-designed achromatic binocular can deliver an attractive optical-performance-to-cost ratio.” Celestron’s surfaced excerpt does not name an individual reviewer. Space.com’s review page identifies the model as a top pick in a large astronomy binocular buying-guide context, while Live Science’s review summary describes it as suited to stargazing and tripod-based observation. These are editorial assessments, not tests conducted for this article.
Manufacturer-listed specifications
The figures below are published by Celestron and have not been independently verified here.
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- OUR LARGEST TRIPOD-MOUNTED BINOCULAR: Giant astronomy binoculars with massive 100mm objective lenses and powerful 25x magnification. Pair them with any tripod for long-distance land-based viewing or astronomical observation.
- WORKS WITH YOUR TRIPOD: Due to their size & weight, we recommend mounting these binoculars on a traditional photo tripod (not included). The built-in ¼”-20 adapter attaches to most tripods in seconds.
- BRIGHT, SHARP VIEWS WITH BaK-4 PRISMS: The SkyMaster is a favorite among those who view in dim conditions near dawn and dusk or at night for astronomy. BaK-4 prisms maximize light throughput to your eye so you see brighter, more detailed images.
- DURABLE AND WATER-RESISTANT: A rubber-armored housing protects your binoculars from damage and provides a secure gripping surface. The water-resistant exterior stands up to tough conditions and unexpected rainy weather.
- UNBEATABLE WARRANTY & CUSTOMER SUPPORT: Buy with confidence from Celestron, a leading optics brand in California since 1960. Your purchase includes a Celestron Limited Lifetime US Warranty & US-based expert tech support.
| Specification | Celestron-listed value |
|---|---|
| Magnification | 25× |
| Objective diameter | 100 mm |
| Objective focal length | 417.32 mm |
| Angular field of view | 3° |
| Linear field of view | 156 ft at 1,000 yd (52 m at 1,000 m) |
| Exit pupil | 4 mm |
| Eye relief | 15 mm |
| Close focus | 80 ft (24.4 m) |
| Interpupillary distance | 56–72 mm |
| Diopter adjustment | ±5 |
| Twilight factor | 50 |
| Relative brightness | 16 |
| Limiting stellar magnitude | 12.50 in ideal conditions; 11.50 in moderate conditions; 10.50 in poor conditions |
| Optics and prisms | Multi-coated optics; BaK-4 prism glass; prism coatings listed as N/A |
| Weight | 140 oz (3,969 g) |
| Dimensions | 256 × 130 × 388 mm |
| Environmental protection | Water resistant; not nitrogen filled |
| Tripod interface | Integrated rigid photo tripod adapter |
Why a tripod is part of the buying decision
At nearly 4 kg, these binoculars are heavy before adding the support equipment needed for stable viewing. Their 25× magnification also makes small movements apparent in the view. Celestron includes an integrated tripod adapter and identifies the binoculars as tripod adaptable, but its listed included items do not include a tripod. In practice, plan for a sturdy photo tripod and a compatible head with adequate load capacity; check the exact interface and support capacity before buying a mount. No particular tripod model is established by the product information.
The 3° field, 4 mm exit pupil and 15 mm eye relief are useful comparison points when evaluating other large binoculars. Whether those values suit you depends on your observing priorities and fit; the specifications alone do not establish a particular level of image quality or comfort.
Rank #2
- POWERFUL 25X MAGNIFICATION: Giant astronomy binoculars with massive 70mm objective lenses and 25x power. Pair them with any tripod for long-distance land-based viewing or astronomical observation.
- WORKS WITH YOUR TRIPOD: Due to their size/weight and high magnification, most users mount SkyMaster binoculars on a traditional photo tripod (not included). The built-in ¼”-20 adapter attaches to most tripods in seconds.
- BRIGHT, SHARP VIEWS WITH BaK-4 PRISMS: The SkyMaster is a favorite among those who view in dim conditions near dawn and dusk or at night for astronomy. BaK-4 prisms maximize light throughput to your eye so you see brighter, more detailed images.
- DURABLE AND WATER-RESISTANT: A rubber-armored housing protects your binoculars from damage and provides a secure gripping surface. The water-resistant exterior stands up to tough conditions and unexpected rainy weather.
- UNBEATABLE WARRANTY & CUSTOMER SUPPORT: Buy with confidence from Celestron, a leading optics brand in California since 1960. Your purchase includes a Celestron Limited Lifetime US Warranty & US-based expert tech support.
Terrestrial viewing, weather protection and included items
The manufacturer describes the model as suitable for long-distance terrestrial viewing as well as astronomy. Its 80 ft (24.4 m) close-focus specification is not intended for nearby subjects. The listing calls the binoculars water resistant, but also says they are not nitrogen filled. Do not treat those descriptions as a promise of waterproofing or fogproofing.
Celestron lists objective caps, a rainguard, a nylon carrying case, a neck strap, a lens cloth and an instruction manual as included items. The listing does not include a tripod.
Rank #3
- 25x magnification porro prism binocular
- Giant 100 mm objective lens offers maximum image brightness in low-light and long-range conditions
- Ultra sharp focus across the field of view
- Individual Eyepiece Focus to ensure optimal focus position
- Extendable aluminum tripod legs with heavy-duty mount head
Price and availability
Celestron’s U.S. storefront listing showed the SkyMaster 25×100 at $519.95 and in stock when surfaced. Price and stock can change, so check Celestron’s current listing before purchasing. The manufacturer page lists Amazon, B&H, Best Buy, High Point Scientific, OPT, Adorama and other dealers, but that does not establish the current price, stock or seller quality of any individual marketplace offer.
How to decide whether it suits you
It may fit your needs if
- You want a high-magnification binocular for stargazing or distant terrestrial subjects.
- You have, or are prepared to buy, a sturdy tripod and compatible head.
- You are comfortable comparing the manufacturer’s specifications and surfaced editorial reviews rather than relying on a hands-on assessment in this review.
Consider other options if
- You need binoculars for handheld use, frequent travel or quick viewing without setting up support.
- You require a model explicitly specified as waterproof or nitrogen filled.
- You are comparing it with another SkyMaster model, such as the 25×70: compare magnification, field of view, exit pupil, eye relief, weight, dimensions, focus system, protection, tripod interface, included accessories, warranty and current price. The available specifications do not support a complete, like-for-like comparison with the 25×70, and aperture alone does not make one model universally better.
Important solar-viewing warning
Never look directly at the Sun through the SkyMaster 25×100, or project the Sun’s image through it. Permanent and irreversible eye damage may result. Celestron also warns that projecting a solar image onto a surface can heat and damage the binoculars and attached accessories, and says not to leave the optic unsupervised.
Quick Recap
Best Value
- POWERFUL 20X MAGNIFICATION: Giant astronomy binoculars with massive 80mm objective lenses and 20x power. Pair them with any tripod for long-distance land-based viewing or astronomical observation.
- WORKS WITH YOUR TRIPOD: Due to their size & weight, most users mount SkyMaster binoculars on a traditional photo tripod (not included). The built-in ¼”-20 adapter attaches to most tripods in seconds.
- BRIGHT, SHARP VIEWS WITH BaK-4 PRISMS: The SkyMaster is a favorite among those who view in dim conditions near dawn and dusk or at night for astronomy. BaK-4 prisms maximize light throughput to your eye so you see brighter, more detailed images.
- DURABLE AND WATER-RESISTANT: A rubber-armored housing protects your binoculars from damage and provides a secure gripping surface. The water-resistant exterior stands up to tough conditions and unexpected rainy weather.
- UNBEATABLE WARRANTY & CUSTOMER SUPPORT: Buy with confidence from Celestron, a leading optics brand in California since 1960. Your purchase includes a Celestron Limited Lifetime US Warranty & US-based expert tech support.
Rank #4
- 25x magnification porro prism binocular
- Giant 100 mm objective lens offers maximum image brightness in low-light and long-range conditions
- This smartphone Adapter connects your smartphone to a telescope, binocular, spotting scope, or microscope, so you can capture images and video through the eyepiece.
- Works with most smartphone devices.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
