Good eye relief
If you need to observe while wearing spectacles, the rubber eye cups fold down easily. The eye lenses are recessed slightly for protection, but there is enough of the specified 20mm eye relief available to enable the entire field of view to be visible with spectacles.
just outside the edge of the field of view, and none at all with first magnitude stars in the same position.
We tested the Stellar IIs under a variety of sky conditions, mounted on a sturdy photographic tripod with a fluid video head. Stars consistently came to a good focus over the central 70 per cent of the field of view. We noticed a small amount of off-axis chromatic aberration on the Moon’s terminator and limb, but the on-axis colour correction is good. This aids the colour rendition, which is excellent. The different hues of Alderamin (Alpha (_) Cephei) and Zeta (c), Delta (b) and Mu (µ) Cephei were immediately obvious, and the contrasting gold and sapphire of Albireo (Beta (`) Cygni) was almost vibrant. We could easily split Albireo into its two components and, despite some field curvature, could see that the star was a double over the central 85 per cent of the field of view.
This was all very impressive, but where these binoculars really excelled was on open clusters and extended deep-sky objects such as galaxies and bright nebulae. The Pleiades leapt out at us, its collection of hot bluewhite stars blazing like diamonds under a spotlight; both the southern Milky Way and the Cassiopeia region were filled with knots of stars and – even under suburban skies – the North America Nebula (NGC 7000) was obvious as a brightening of the sky background. The contrast is very good and, when the constellation Cygnus and Aquila were at their highest in the late summer sky, their dark nebulae gave a 3D effect to the Milky Way.
The Helios Stellar II 16x80s are a significant step up from typical ‘starter’ binoculars, so if you’ve been bitten by the binocular astronomy bug and want something that will show you considerably more without stretching your finances as much as premium binoculars will do this would be an excellent choice.
Good quality carry-case
The military-style, woven nylon case feels satisfyingly robust and has enough padding to offer good protection to your investment. It seals with a side-release buckle, and the same device is used to attach the webbing shoulder strap. It has very substantial belt loops.