The Celestron SkyMaster 25×100 gives you 25× magnification and 100 mm objectives, but its 3,969 g (140 oz) weight makes tripod-supported viewing central to the decision. Celestron includes an integrated tripod adapter, not a tripod. Its published specifications make it a candidate for astronomy and long-distance viewing; they do not establish how a particular sample performs in the field.
What the SkyMaster 25×100 is—and what it asks of you
Item 71017 is a large-aperture binocular built around 25× magnification and 100 mm objective lenses. Celestron positions it for astronomy and long-range terrestrial viewing. The combination is intended to bring distant subjects into view while gathering light through large objectives, but the binocular’s weight and magnification make a stable support a practical requirement for sustained observation, rather than a casual handheld option.
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Celestron lists multi-coated optics and BaK-4 prism glass. These are manufacturer specifications, not independent laboratory measurements. The company’s listing also reproduces an excerpt labeled “Astronomy Now Review – July 2021 Edition”: “The SkyMaster 25×100 proves that a well-designed achromatic binocular can deliver an attractive optical-performance-to-cost ratio.” The excerpt does not name an individual reviewer.
Specifications at a glance
The following values are published by Celestron and have not been independently verified here.
#1 Best Overall
- 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 |
| Focus system | Individual eyepiece focus |
| Weight | 3,969 g (140 oz) |
| Dimensions | 256 × 130 × 388 mm |
| Tripod connection | Integrated, rigid photo tripod adapter |
| Environmental protection | Water resistant; not nitrogen filled |
The 3° field, 4 mm exit pupil and 15 mm eye relief are useful points of comparison when evaluating other large binoculars. They do not, by themselves, establish image quality or comfort for an individual observer.
How it fits astronomy and terrestrial viewing
For astronomy
The 100 mm objectives and 25× magnification are the headline specifications for stargazing. Celestron publishes limiting stellar magnitude figures under ideal, moderate and poor conditions, but those figures are manufacturer-listed values, not a guarantee of what an observer will see. Actual views depend on observing conditions and setup; no independent performance measurements are established here.
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.
Space.com has a review page for this model and its surfaced buying-guide result identifies it as a top pick for large astronomy binoculars. Live Science’s surfaced review summary describes it as suited to stargazing and tripod-based observation. These are independent editorial sources, not tests performed for this review.
For distant land viewing
Celestron also describes the model as suitable for long-range terrestrial use. The 80 ft (24.4 m) close-focus specification means it is not designed for nearby subjects. Its 3° angular field is relatively specific for scanning: when comparing alternatives, consider field of view alongside magnification, not just objective size.
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
Mounting and practical handling
At 3,969 g, the binocular is heavy enough that a stable photo tripod and compatible head are practical necessities for extended viewing. Celestron supplies an integrated rigid tripod adapter and identifies the model as tripod adaptable, but does not include a tripod in the listed package. Check the mount’s load capacity and physical compatibility before buying a support; no particular tripod or head is specified by Celestron in the listed material.
The individual-eyepiece focus system is another handling detail to consider. If you are used to center-focus binoculars, compare the focus method and how you expect to use the binoculars before choosing this model.
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.
Weather protection and included items
Celestron lists the SkyMaster 25×100 as water resistant and explicitly says it is not nitrogen filled. Do not treat that description as a claim that the binocular is waterproof or fogproof.
The listed included items are objective caps, a rainguard, nylon carrying case, neck strap, lens cloth and instruction manual. A lens cloth is included, so a separate cleaning kit is optional rather than a stated requirement.
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.
Price, availability and buying decision
Celestron’s U.S. storefront listing showed the item in stock at $519.95 when surfaced. Price, stock and dealer availability can change, so check the current Celestron listing before buying. The listing names retailers including Amazon, B&H, Best Buy, High Point Scientific, OPT and Adorama; it does not establish the current price or seller quality of a particular marketplace offer.
The SkyMaster 25×100 is most compelling if you specifically want 25× binoculars with 100 mm objectives and are prepared to use a substantial tripod setup. If portability, handheld use, a wide field, or weather-sealing assurances are priorities, compare other models by magnification, field, exit pupil, eye relief, weight, dimensions, focus system, mounting interface, included accessories, warranty and current price—not by aperture alone. Celestron’s related 25×70 SkyMaster is another model to investigate, but the available specifications here are insufficient for a complete, fair comparison.
Sun-viewing warning
Never look directly at the Sun through these binoculars, even briefly. Celestron warns that permanent, irreversible eye damage may result. Do not project the Sun’s image onto a surface: concentrated heat can damage the binoculars and attached accessories. Do not leave the optic unattended during any attempted solar projection.
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Quick Recap
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.
