The Celestron SkyMaster DX 8×56 takes a different approach to many large astronomy binoculars. Instead of combining large objective lenses with high magnification, it pairs 56mm objectives with a relatively low 8× magnification, producing a bright, expansive view that is particularly well suited to sweeping the night sky.
At around 2.4 lb (1.08 kg), it is considerably easier to use handheld than giant binoculars such as the SkyMaster 25×100, although its extra weight compared with typical 8×42 or 10×50 binoculars becomes noticeable during longer observing sessions.
The most distinctive feature is its 7mm exit pupil — unusually large by modern binocular standards. That can make the 8×56 particularly appealing for dark-sky observing, although how much of that light reaches the eye depends on the observer’s own pupil dilation.
A 7mm Exit Pupil for Dark Skies
Pairing 56mm objective lenses with 8× magnification produces a 7mm exit pupil, meaning each eyepiece delivers a relatively wide beam of light to the observer’s eye. Under genuinely dark skies, this can produce bright, relaxed views that work particularly well for sweeping Milky Way star fields, large open clusters and extended deep-sky objects.
There is an important qualification, however. To take advantage of the full 7mm exit pupil, the observer’s own dark-adapted pupils must open to roughly the same diameter. If they dilate to only 5mm, for example, some of the light leaving the binocular falls outside the pupil and the effective aperture is reduced.
That doesn’t make the binocular ineffective for observers with smaller pupils — the low 8× magnification and 5.8° field of view still provide an expansive view of the night sky. It simply means that not everyone will benefit from the full light-gathering potential of the 56mm objectives.
Wide-Field Views at 8×
With 8× magnification and a 5.8° field of view, the SkyMaster 8×56 shows a much larger area of sky than high-powered astronomy binoculars. That makes it easier to find objects and particularly enjoyable for exploring broad regions of the Milky Way rather than concentrating on individual small targets.
Large open clusters such as the Pleiades and Hyades suit this style of observing particularly well, while the relatively low magnification also makes it easier to follow larger star patterns and move between objects using recognizable naked-eye landmarks.
The 5.8° field isn’t exceptionally wide for an 8× binocular, but that misses the point of the 8×56 configuration. Its appeal comes from combining a usefully broad field with larger 56mm objectives and a bright 7mm exit pupil, rather than maximizing field of view alone.
Handheld, but Heavier Than Typical Binoculars
At around 2.4 lb (1.08 kg), the SkyMaster 8×56 is practical to use handheld, and its relatively low 8× magnification helps keep normal hand movements from becoming too distracting.
It is still noticeably heavier than many conventional 8× binoculars, however, and holding it steadily for extended periods can become tiring. For longer observing sessions, supporting your arms or using a tripod and suitable binocular adapter can provide a steadier and more comfortable view.
This gives the 8×56 considerably more flexibility than high-powered giant binoculars. It can be taken outside and used immediately for a quick look at the sky, while still offering the option of mounting it for longer observing sessions.
Waterproof and Nitrogen Filled
The SkyMaster 8×56 is waterproof and nitrogen filled, making it better suited to outdoor observing in damp conditions than binoculars with only basic water resistance. The sealed body helps prevent moisture from entering the binocular, while nitrogen filling reduces the risk of internal fogging when temperature and humidity change.
That doesn’t eliminate the normal problem of external condensation forming on the lenses when binoculars are brought between cold and warm environments, but it provides useful protection for an instrument likely to spend much of its time outdoors at night.
The binocular also has a rubber-armored exterior, providing additional protection and a more secure grip when handling it in the dark.
Comfort and Focusing
The SkyMaster 8×56 provides 18mm of eye relief, giving observers some room to position their eyes behind the eyepieces. This can be useful for eyeglass wearers, although whether the full field of view is visible with glasses will depend on the individual observer and how the binocular fits them.
Unlike the individually focused SkyMaster 25×100, the 8×56 uses a central focusing wheel, with a separate diopter adjustment allowing differences between the observer’s two eyes to be compensated for. This makes focusing quicker and also makes the binocular more convenient for daytime use, where viewing distances change frequently.
For astronomy, focusing is generally a set-and-forget operation once the stars are sharp. Combined with the relatively low 8× magnification, this makes the SkyMaster 8×56 straightforward to use for relaxed scanning of the night sky.
Limitations to Consider
The SkyMaster 8×56’s main physical compromise is its size and weight. Although practical to use handheld, at around 2.4 lb (1.08 kg) it is substantially heavier than many 8× binoculars, so extended observing sessions can become tiring without some form of support.
Its 7mm exit pupil will not provide the same advantage for every observer. If the observer’s dark-adapted pupils do not open to around 7mm, some of the available light cannot enter the eye. Under light-polluted skies, the large exit pupil can also produce a brighter background sky.
Finally, the 5.8° field of view is useful rather than exceptionally wide for an 8× binocular. The SkyMaster 8×56 therefore makes most sense for observers attracted to its combination of low magnification, relatively large aperture and bright views rather than those simply looking for the widest possible binocular field.
Who Is the SkyMaster 8×56 Best For?
The SkyMaster 8×56 is best suited to observers who enjoy low-power views of the night sky and want more aperture than smaller handheld binoculars provide. Its combination of 8× magnification, 56mm objectives and a 7mm exit pupil is particularly attractive for dark-sky Milky Way fields, open clusters and other large targets. It is less compelling for observers under substantial light pollution, those who prioritize a lightweight binocular, or those whose eyes cannot make full use of the large exit pupil.
Specifications
- Magnification: 8×
- Objective Diameter: 56mm
- Prism Type: Porro, BaK-4
- Field of View: 5.8°
- Exit Pupil: 7mm
- Eye Relief: 18mm
- Close Focus: 25 ft (7.6m)
- Weight: 38 oz (1.08 kg)
- Optical Coatings: Fully multi-coated
- Focusing System: Center focus with diopter adjustment
- Weather Protection: Waterproof
- Nitrogen Filled: Yes
- Tripod Adaptable: Yes