Celestron SkyMaster 25x70 Porro Prism Binoculars — A high-magnification 25×70 Porro binocular for detailed lunar, astronomical and long-range terrestrial observation, supplied with a binocular tripod adapter.
High Magnification in a 70mm Format
At 25×, this model reveals smaller details than the 12×60 or 15×70 versions, while the 70mm objectives retain useful light gathering. The narrower 2.7° field rewards careful aiming and stable support.
Optical Design and Focusing
BaK-4 prisms and multi-coated optics help maintain contrast and transmission. A centre-focus wheel and right-eyepiece dioptre provide convenient adjustment, while the 2.8mm exit pupil suits bright astronomical targets and daylight long-range observation.
The published field of view is 2.7°, equivalent to 47m at 1,000m. Close focus is 23m (75ft), so this model is intended primarily for medium- to long-distance subjects.
Tripod Use and Weather Protection
The included binocular adapter allows the SkyMaster 25x70 to attach to a suitable tripod. A tripod is strongly recommended because 25× magnification amplifies hand movement; the tripod itself is not included.
Weather protection: Water resistant. It is not nitrogen filled and should not be treated as fully waterproof.
What Is Included?
- SkyMaster 25x70 binoculars
- Binocular tripod adapter
- Objective lens caps
- Eyepiece rainguard
- Neck strap
- Nylon carrying case
- Lens-cleaning cloth
- Five-language SkyMaster instruction manual
Please note: A tripod, solar filters and any item not listed above are not stated as included.
Specifications
Optics
| Optical design | Porro prism binocular |
|---|---|
| Magnification | 25× |
| Objective diameter | 70mm |
| Objective focal length | 279.63mm |
| Angular field of view | 2.7° |
| Linear field of view | 47m at 1,000m |
| Exit pupil | 2.8mm |
| Eye relief | 13mm |
| Close focus | 23m (75ft) |
| Interpupillary distance | 56–72mm |
| Dioptre adjustment | -4 to +8 |
| Focusing system | Centre focus with right-eyepiece dioptre |
| Optical coatings | Multi-coated |
| Prism glass | BaK-4 |
| Twilight factor | 41.83 |
| Relative brightness | 7.84 |
| Limiting stellar magnitude | 11.73 ideal; 10.73 moderate; 9.73 poor conditions |
Construction and Size
| Weather resistance | Water resistant |
|---|---|
| Nitrogen filled | No |
| Tripod mounting | Tripod adaptable; tripod adapter included |
| Carrying case | Nylon carrying case |
| Dimensions | 220 × 110 × 280mm (8.7 × 4.3 × 11 inches) |
| Binocular weight | 1.474kg (52oz) |
Solar Safety
Warning: Never look at or near the Sun through these binoculars.
These are not solar binoculars and do not include certified solar filters. Direct or nearby views of the Sun can cause immediate and permanent eye injury.
Do not attempt solar projection and do not attach improvised or eyepiece-mounted filters.
Instruction Manual
The official Celestron documentation is provided in English, French, German, Italian and Spanish.