If you want a step up from budget binoculars without breaking the bank, the optical and mechanical qualities of these binoculars make them a strong contender.
Pros: Substantial quality improvement over budget models.
Cons: Some optical aberrations.
The Celestron SkyMaster 15×70 Pro binoculars, at first blush, appear to be sturdy and well-made. The center-focus wheel, hinge, and right eyepiece diopter adjuster all work smoothly, with sufficient resistance to make accidental adjustment unlikely. The anti-reflective coatings are properly applied and effective. The full-sized prisms are made of high-index glass, and secured in a cage. You’ll also find well-fitting tethered lens caps at both ends, a comfortable neoprene neck strap, and a substantial padded case.
In a recess in the packaging you will find the first unique feature – there are two sets of eye cups: normal and winged. The winged eye cups are ideal for shielding your eyes from lateral illumination, but need to be folded down to use eyepiece caps. Unfortunately, the eye cups have a tendency to come off unless you unfold them carefully, and refitting them in the dark is a fiddly process.
The second unique feature of the binoculars is much more successful. The proprietary tripod adapter is designed to accept a removable red dot finder (RDF) mounting rail. Some people find it difficult to accurately aim mounted straight-through binoculars, especially at high elevations, but an RDF makes it trivially easy.
The view is sharp and flat over the central half of the field of view, but aberrations, particularly field curvature, combine to affect it outside of this. Delta Cephei (40 arcsecond separation, magnitudes +4.1 and +6.1) started to deteriorate noticeably at 50% out, but the stars were still cleanly split to about 75% out if I focused out the field curvature. There is vignetting in the outer 10% or so. Control of false color (chromatic aberration) is good on axis, but becomes noticeable on bright objects (e.g. the lunar limb) once the object is off-axis. Color rendition is very good. During my testing, the varied colors of the stars in Orion’s Meissa cluster were obvious, and Uranus glowed turquoise.
Common astronomical objects were easy to render when I tried the binoculars out. M51 looked elongated, but did not show any core condensations. The Andromeda Galaxy was bright, and showed good differentiation of the core; I could distinguish a sharper cut-off in brightness from the dust lane at the nearer edge. The Orion Nebula showed some structure, despite being low in the sky at the time of testing, and I could fleetingly see two Trapezium stars (17 arcseconds apart). Jupiter was a clean disc, with the four Galilean satellites well-defined on either side of it.
In summary: pleasant to use.
Original Review: http://binocularsky.com/binoc_reviews.php