Helios Stellar II
Extras: Wide, neoprene neck strap; tethered objective caps and rain-guard; robust, lightly padded fabric case
Supplier: Optical Vision Ltd:
Tel: 01359 244200
The Helios Stellar II binoculars are the only ones in this test that have individual eyepiece focusing.
This is the preferred option for astronomy, meaning you can set the focus and then leave it alone.
These are also the heaviest pair, which means that they are the most likely to tire your arms, although we did find that their mass also helps to reduce shake.
We were impressed with the brightness and excellent colour rendition of the image, which is sharp over the central 80 per cent of the 6.5° field of view.
This makes them ideal for scanning the sky.
They have several useful features, including tethered lens caps for the objective lenses and the eyepieces.
By having these caps attached to the binoculars, they won’t get lost and you’re probably more likely to use them, too.
They are covered in a substantial, ribbed rubber armour that offers protection against everyday knocks, and gives a secure grip even when the binoculars are damp from dew
Verdict: If you want 10x50s specifically for astronomy, these would be a very good choice.
For: Bright images, good colour rendition, wide field
Against: Relatively heavy
Overall Score: 4/5
Opticron Imagic TGA WP
Extras: Wide, nylon neck strap; tethered objective caps and rain-guard; semi-rigid vinyl case
Supplier: Opticron UK
Tel: 01528 726522
The Opticron TGA binoculars are more than 100g lighter than any of the other Porro prism binoculars in this test group, but this doesn’t come at the expense of ruggedness.
Not only are they covered in a substantial rubber armour, but they come with a semi-rigid case that offers excellent protection against the rigours of regular, varied use.
Their field of view is on the narrow side at 5.3°, but this is compensated for by extremely good colour correction and colour rendition.
Star colours were vibrant in the eyepieces.
Images were bright and stars were tack-sharp across the middle 75 per cent of the field of view.
We thoroughly enjoyed scanning colourful star-fields with these.
They are very well-balanced, which makes them feel even lighter than they actually are.
This means you can use them for long periods before aches and strains set in.
The ribbing on the prism housing gives a very secure grip, even if they are damp with dew.
Verdict: A very versatile, lightweight all-rounder, which is also useful for astronomy
For: Excellent colour rendition; lightest Porro on test
Against: Relatively narrow field of view
Overall Score: 4/5
Nikon Action EX
Extras: Wide, nylon strap with soft anti-slip neck patch; tethered rain-guard, tetherable objective caps; lightly padded fabric case
Tel: 01603 486413
From the moment you take these binoculars out of their lightly padded case, they ooze quality.
They have a robust feel in the hand and everything – hinge, focusing, twist-up eye-cups – works smoothly with just the right amount of stiffness to prevent accidental readjustment.
The eyepiece rain-guard is tethered, and the objective caps can be secured to the binoculars’ strap to prevent you mislaying them.
They are just as impressive under the stars, which snap to focus anywhere in the central 85 per cent of its 6.5° field of view, giving a bright, crisp, high-contrast image.
Colour rendition and control of false colour are both very good.
There is just enough eye relief for spectacle-wearers to be able to see the entire field of view.
They are well-balanced and hence relatively easy to hold steady, and the chunky lugs on the right eyepiece dioptre make adjustments easy, even when you’re wearing thick gloves.
The rubber armour stops them from becoming slippery when wet with dew.
Verdict: Very capable general-purpose binoculars that are good for both day and night-time use
For: Bright, good colour; wide flat field
Against: Heaviest centre-focus binocular
Overall Score: 4.5/5
Extras: Wide, padded neck strap; tethered objective caps and rain-guard; lightly-padded fabric case
Supplier: First Light Optics
Tel: 01392 791000
The Vortex Crossfire is a good example of how modern manufacturing processes have narrowed the gap in optical quality between Porro and roof prism binoculars of similar prices.
The 6.1° field of view is on a par with the Porros and flat enough that we could keep Albireo split into two components over the central 90 per cent.
Colour rendition was excellent; not only do the deeply coloured stars seem vibrant, but the subtle differences between similarly coloured ones are easily visible as well.
The focus is smooth and precise and the short-hinge design leaves more room for your fingers, making these binoculars very comfortable to hold.
There is enough eye-relief to allow you to observe while wearing spectacles.
The objective lens caps are tethered to the screw in the adaptor bush in the hinge, so they become untethered if you mount the binoculars.
Apart from that, the only other niggle is the high minimum interpupillary distance (IPD: 60.5mm), which is an inevitable feature of the roof prism design used for 50mm aperture.
Verdict: If you want a compact but capable and versatile 10×50, this could be ideal for you
For: Bright, sharp views, superb colour; lifetime guarantee
Against: Large minimum IPD
Overall Score: 4.5/5
Celestron Outland X
Extras: Narrow, nylon neck strap; tethered objective caps and rain guard; lightly padded fabric case
Supplier: David Hinds Ltd
Tel: 01525 852696
Weighing just shy of 800g, these are easily the lightest binoculars on test.
We found them very comfortable to handle and enjoyed the sharp on-axis views they gave.
Colour correction was quite good, as was the colour rendition – it was easy to distinguish the orange of Herschel’s Garnet Star (Mu (μ) Cephei) from the brilliant white of Alderamin (Alpha (α) Cephei) and the yellow of Zeta (ζ) Cephei.
The eye relief is a very short 10mm, and some of this is taken up by the recess of the eye lens.
Consequently, we were unable to see the entire field of view when we tried observing while wearing spectacles.
They are specified as being ‘multi-coated’ and, although the anti-reflective coatings on the lenses were effective, the image was noticeably dimmer than with the other binoculars in this test, all of which were specified as ‘fully multi-coated’.
In common with most 50mm roof prism binoculars, the minimum interpupillary distance is limited by the design and is relatively large at 61mm.
Verdict: Okay if you want some lightweight, general-purpose binoculars for occasional astronomical use
For: Good colour rendition, lightweight
Against: Inadequate eye relief, large minimum IPD
Overall Score: 3/5
Pentax SP WP
Extras: Wide nylon strap with soft neck patch, untethered caps and rain-guard, lightly padded, strapless fabric case
Tel: 02033 845187
The Pentax SP series of Porro prism binoculars is characterised by an unusual focusing mechanism.
Gone is the familiar eyepiece bridge, because all the workings are internal, aiding with waterproofing.
It also allows them to incorporate an enormously useful feature: focus locking.
This is achieved by sliding the centre-focus band along its spindle.
Another helpful design feature is the inclusion of large lugs on the right eyepiece dioptre, which make it easy to adjust even with thick gloves.
The first thing you notice about the image these binoculars produce is how much of it is very sharp: the two components of Albireo only merged in the outside 10 per cent of the field of view.
However, this field of view is only 5°, the narrowest of all the binoculars we tested.
Colour rendition is faithful, and on-axis chromatic aberration is very well controlled; false colour only appeared on the lunar limb towards the edge of the field.
The minimum interpupillary distance of 52mm makes these binoculars suitable for people with small faces or close-set eyes.
Verdict: Optically and mechanically very good, these binoculars will suit a wide range of people
For: Sharp image, locking focus
Against: Narrow FOV; ill-fitting, untethered lens caps
Overall Score: 4/5
These reviews originally appeared in the December 2018 issue of BBC Sky at Night Magazine