A Work Commenced May 28 2024

Preamble

Product: Sky Rover Banner Cloud 10 x 50

Country of Origin: China

Chassis: Magnesium alloy overlaid by protective rubber

Exit Pupil: 5.0mm

Eye Relief: 18mm

Field of View: 136mm@1000m(7.5 angular degrees)

Dioptre Compensation: +\-4

Coatings: Fully broadband multicoated, Phase corrected Schmidt Pechan prisms, hydrophobic coatings on ocular and objective lenses

ED glass: Yes(2 elements)

Field Flatteners: Yes

Waterproof: Yes, 1m/30 mins

Nitrogen Purged: Yes

Close Focus: 3m advertised, 2.97m measured

Light Transmission: 90-92%

Tripod Mountable: Yes

Dimensions:17.6 x 13cm

Weight: 1040g advertised, 1020g measured without rain guard and objective covers.

Accessories: Soft padded carry case, objective covers, ocular rain guard, padded neck strap, microfibre cloth, instruction manual

Warranty: 3 Years(to be possibly negotiated)

Price:$599.00(plus shipping and import duty)

In all my years of reviewing binoculars for the consumer market, I’ve never witnessed such a fever-pitched interest in the new high-performance roof prism wonder glasses manufactured by the United Optics Company, based in Kunming, China: the  Sky Rover Banner Cloud(SRBC).
The 8 x and 10 x 42 models are proving to be incredibly popular, despite a few quality control issues expected of any new product, and especially as more and more favourable user reports emerge.

In this review, I wish to showcase the larger 10 x 50 model, which was purchased via Aliexpress and took a little over 3 weeks to arrive here in Scotland. Let’s take a look ‘round the instrument.

Ergonomics

Just like the 8 x 42 model, everything works perfectly. The twist-up eye cups are robust, clicking into place firmly. These are as good as I’ve seen on the most expensive European brands but most resemble those found on Leica binoculars. And like the 8 x 42, it offers five positions in all. I found the optimal positioning for my eyes was three clicks up as this allowed me to see the field stops clearly. Eye relief is a bit tighter on the 10 x 50 than on the smaller 8 x 42. With the eyecups fully retracted I could comfortably image the majority of the field with ordinary glasses. Only the last five per cent or so remained out of view. I suspect that those who wear flatter/ lower profile glasses should see the entire field easily.

The focus wheel is exactly the same size on the 10 x 50 as on the smaller 42mm models, yet looks relatively smaller owing to the larger frame of the 50mm model. I personally really like the kinematics of the SRBC focuser. It is smooth as silk and beautifully responsive, with no free play or bumps moving it through its travel from one end to the other. And like the 8 x 42, it rotates through 1.5 revolutions anticlockwise moving from closest focus to infinity and beyond. I was relieved to see that the 10 x 50 SRBC will accommodate those who have severe myopia with its generous beyond infinity focus travel.  

The right eye dioptre ring is nice and stiff, keeping its position firmly while in field use. 

Both the ocular and objective lenses have immaculately applied antireflection coatings with no streaks or holes visible. Seen straight on they almost disappear. 

The green rubber armouring on the 10 x 50 is exactly the same as on the 42mm models. It’s undoubtedly tough but I would have liked a little bit more texture to the touch. 

Handling is excellent. Despite weighing in at just over a kilogram, it’s easy to hold steady, either scanning a landscape or looking intently at a fixed target. 

The supplied padded neoprene strap works very well with the 42mm models but is just a tad lightweight for the larger 50mm format. I would recommend using a slightly more robust strap with these larger instruments for optimal use. That said, I had no discomfort carrying the instrument on two mile walks over level ground. It hangs very well on my chest. 

I also really like the supplied case. It’s very nicely made and definitely travel worthy, comfortably protecting the instrument from shocks. It also accommodates the neck strap attached to the binocular which is not that commonly experienced.

All in all, this is a very well made instrument with nothing I can see that would fail in field use. What’s to give? I’m more than pleased with the ergonomics in handheld mode too. But it can be mated to a bracket for monopod/ tripod mounting simply by unscrewing the cap at the objective end of the bridge. 
Optics

Examining an intensely bright light beam a few metres away showed excellent results with no internal reflections, diffraction spikes or diffused light around the beam. The same was true when I aimed the instrument at a bright street light after dark. Next, taking a look at the area around the exit pupils (see below) you can see they are very dark with no significant light leaks.

The two small circles seen well away from the pupils result from reflections off two screws from light entering from the eyepiece end, as elucidated by Holger Merlitz. They therefore have no effect on the images since your face blocks them off.  To sum up, these results are amongst the best I’ve personally experienced in a binocular and a testimony to the care taken by the staff at the United Optics Company.

As I said before, outstanding optical performance is easy to recognise and this binocular has it in spades.The view through the 10 x 50 SRBC is nothing short of stunning! It presents an enormous, highly immersive 7.5 degree field, with fantastic edge-to edge sharpness. Colours are vibrant, contrast is excellent and the suppression of glare is a real stand-out feature. Even during extensive handling, the extra magnification of 10 x over 8 x is immediately apparent, with finer details popping into view. A 7.5 degree field is much more reminiscent of a typical 8 x birding binocular, so having this size field in a 10 x 50 format is a really delightful visual treat. Just compare that to the Swarovski EL 10 x 50  which presents a mere 6.6 degrees in comparison! Off-axis aberrations are very effectively controlled with only a slight amount of pincushion distortion creeping in near the edge of the field. I did detect a slight rolling ball effect while panning but I considered it fairly mild and hardly noticeable in most  circumstances. Performing tests on some of the brighter stars of the early summer sky, like Vega and Deneb, collimation was spot on with the instrument showing them as tightly focussed pinpoints of light from centre to edge of field. A full assessment of its astronomical capabilities will need to wait until I can get a chance to test it under darker skies. – so watch this space!

Thanks to the ED optical components, longitudinal chromatic aberration is essentially absent from the central 60 per cent of the field, with only a sliver of lateral colour creeping in on very high contrast targets nearer the field stops. Those who are especially sensitive to chromatic aberration will be delighted with the performance of this binocular. To summarise, the 10 x 50 passes all daylight optical tests summa cum laude. I consider these SRBC binoculars to be nothing short of revolutionary, especially when you factor in their retail price.

Notes from the Field:

Getting the right eyecup position took a bit of experimentation. Fully extended, I was unable to engage with the entire field and I noticed a bright arc of whitewashed light at the bottom of the field next to the field stop. Moving the cups two steps down allowed me to see the entire field of view and also removed the glare. 

Whether in dull, overcast conditions or during bright sunshine the views through the SRBC 10 x 50 are incredibly sharp and highly immersive. Details of close up targets and at distance are superb. The silky smooth focus wheel makes it practically effortless to move from targets set only a few metres away all the way out to infinity. Despite its sizeable mass, this feature makes it a surprisingly effective birding glass, which is also facilitated by its huge field of view. I noticed a pronounced enhancement of stereopsis on targets in the middle distance moving from the 8 x 42 to the 10 x 50. Closest focus was measured at 2.97m on my unit: a very good result for a binocular with these specifications. Although a 10 x 50 is not normally my natural choice for exploring forest terrain, the SRBC handled it superbly, much better in fact than an excellent 10 x 35 Porro prism binocular which made me a little nauseous in comparison.  I attribute this its ultra-wide field, comfortable close-focusing distance and its ultra-responsive focus wheel. The extra light garnered by the large objective lenses makes seeing fine detail in poorly illuminated regions of the forest floor very easy. It particularly excels in scanning wide open terrain and observing at distance over water. 

Submersion Tests

In my review of the 8 x 42 SRBC, I demonstrated its cold temperature capability by placing the instrument in my freezer at -20C for one hour which resulted in no loss of functionality of the focus wheel and no ill effects to the optics. To follow on from this, I subjected the larger 10 x 50 SRBC to a water immersion test by plunging the instrument into a basin of cold water and leaving it submerged for 2 minutes. The set up is shown below. Achtung; this is not for the faint of heart!

The 10 x 50 SRBC immersed in a basin of cold tap water for 2 minutes.

After immersion I took it out, dried it down with a towel and let it sit at room temperature for an hour before placing it in a dry box with desiccant as any sensible person ought to do. I then placed it in a warm cupboard where it was stored indefinitely. On five successive days I brought it out into the cool evening air on 2-mile walks for about an hour to see if any water vapour would condense on the optical components inside the barrels. The results were extremely encouraging: I could see no encroach of water and no fogging up of the optics on any of these five days. This result gives me confidence that the SRBC binoculars are rugged and weatherproof. All in all, another hugely impressive result!

Note to the Reader: Please don’t try this at home! I did it so you don’t have to!

Binocular Comparisons

Most of my optical tests of the SRBC 10 x 50 were conducted alongside the optically excellent Japanese-made Nikon EII 10 x 35 because of its very wide field of view and identical 10x magnification.

Carefully comparing the views garnered by both binoculars under different daylight conditions I drew 4 principal conclusions.

1. The 10 x 50 SRBC has a slightly wider field of view than the Nikon EII(7.2 degree field).
2. The SRBC has better longitudinal colour correction owing to its APO billing. Lateral chromatic aberration was also much lower in the SRBC than in the Nikon EII.
3. Contrast and colour saturation was deeper and richer in the SRBC.
4. Edge of field sharpness was significantly better in the SRBC than in the Nikon EII.

Low Light Comparisons

Culcreuch Pond, 23:00 local time, June 1.

On the evening of June 1 we were presented with a cloudless blue sky. A cool northerly air flow caused the temperatures to drop below 10C. This, together with a light breeze prevented any biting midge flies from getting close. It was a perfect evening to test the low light capability of the 10 x 50 SRBC. At this time of year, we get a permanent twilight as the Sun never sinks low enough below the northeastern horizon to create true darkness. Bringing the 10 x 35 Nikon EII along with me, the first thing I noticed was that as the sky darkened to dusky conditions, my dilated eye pupils were picking up some glare, especially when glassing towards the bright northeastern horizon. The 10 x 50 SRBC, in contrast, was stubbornly refusing to show anything like the same level of glare. I attributed this to the brighter hinterland around the exit pupil of the Nikon glass which was now encroaching on the binocular image. The much darker areas around the SRBC pupils made this a much more pleasant experience. I refer you to pages 191 through 195 of Holger Merlitz’s excellent new book, The Binocular Handbook, for more details on this interesting phenomenon. 

Naturally, the SRBC with its larger aperture and exit pupil(5mm vs 3.5mm) compared to the smaller 10 x 35 Nikon glass makes seeing details in low light considerably easier. But I was not quite prepared for what I experienced at about 11pm local time on that evening, while glassing the waters of Culcreuch Pond, about a half mile walk from my home. I was comparing the views of the 10 x 35 with the 10 x 50, when my attention was piqued as I moved the instruments just beyond the brightly reflecting water, as seen on the above photo, into the darker, nether regions, where the trees’ shadows extend. The 10 x 35 was really struggling to make out much detail, but I did pick up some rapid, ghostly movements from it – just above the water. Moving to the larger 10 x 50 glass, I was astonished to discover dozens of flying bats, feasting on the teeming insects hovering over the face of the waters! Just like the Swallows I’ve seen many times doing the same thing in broad daylight, these amazing mammals were swooping down and away from the water’s surface with astonishing agility. How on God’s earth could these tiny, and all but blind mammals negotiate such astonishing manoeuvres in almost complete darkness, and even with sonar? I stood there in silent amazement for a good 15 minutes before the deepening chill brought me to my senses, to summon me home. Needless to say, I’ve been up to the pond a few more times since at these late hours, studying the same phenomenon. Pure dead brilliant! 

Having said all that, I must concede that I prefer the 10 x 35 for stargazing under twilit skies. That’s simply because its smaller exit pupil darkens the sky better than a 5mm exit pupil. For me aesthetics is everything under mid-Summer conditions this far north! I shall endeavour to provide an update on the SRBC’s astronomical capabilities after I’ve tested it under truly dark skies later in the season. So stay tuned for Part 2!

Conclusions & Recommendations

To my mind, the arrival of the Sky Rover Banner Cloud series of binoculars represents a giant leap forward in the intelligent design of sports optics for the burgeoning outdoor enthusiast market: whether birding, astronomy, hunting or travel & leisure, and which now enjoys a global reach. Setting completely new standards in optical quality previously only seen in top quality European brands, these new instruments will enable a whole new section of the consumer market to experience world-class optics at prices hitherto unheard of. For me, the more people who can enjoy the wonders of creation, as revealed by these new instruments the better. It’s all about empowerment. And if you want to call that an ‘agenda,’ then so be it, I’m guilty as charged!

Neil English is the author of 8 books. His latest work, Choosing & Using Binoculars: A Guide for Stargazers, Birders and Outdoor Enthusiasts, explores the fascinating world of binoculars, ranging from the very large to the very small.

De Fideli.

A Work Commenced May 20 2024

Product: Opticron Adventurer T WP 12 x 50

Country of Manufacture: China

Chassis Material: Rubberised Aluminium & Polycarbonate 

Exit Pupil: 4.17mm

Eye Relief: 15mm

Field of View: 95m1000m(5.4 angular degrees)

Coatings: Fully Multicoated on all glass surfaces

Prisms: Porro BAK4

ED Glass: No

Close Focus: 7m advertised

Dioptre Compensation: +/- 4.0

Waterproof: Yes

Nitrogen Purged: No

Tripod Mountable: Yes

Accessories: tetherable rubber objective lens caps, ocular caps, padded neck strap, soft carrying case, microfibre lens cleaning cloth, warranty card & instruction manual.

Weight: 765g advertised, 751g measured

Warranty: 2 Years

Dimensions: 16.9 x 19cm

Price(UK): £95.00

This is going to be a short review. I purchased this Opticron 12 x 50 Porro from Amazon some time ago and only recently opened the package. Unfortunately, when I began looking through it, I quickly realised that the unit was not collimated properly as I was unable to merge the images satisfactorily. A star test after dark confirmed my suspicions. What I can report is my ‘monocular’ impressions only. Like the several other models in the Adventurer T WP series, it offers up nice, contrasty images with good control of glare. Internal reflections were kept at bay too. I only detected a very minor reflection while observing the full Moon. It has a fairly narrow but well-corrected field of view though at 5.4 degrees. The sweet spot is decently large, with mild field curvature and moderate pincushion distortion creeping in near the field stops. Colour correction is very good for this non-ED 12x model but can be picked up on high contrast targets in poor lighting conditions. 

It’s a pity the instrument was received with the optics out of alignment as otherwise it seems to be a very decent performer for the modest price paid. With a two-year warranty from Opticron, I will send it back for either a repair or a replacement.  It does however, serve to illustrate another general trend in binocular optics: higher power models are more difficult to collimate accurately than those employing lower magnifications. 

De Fideli.

A Work Commenced September 17 2023

Product: SvBony SA204 10 x 50

Country of Manufacture: China

Exit Pupil: 5mm

Field of View: 114m@1000m(6.5 angular degrees)

Eye Relief: 19mm

Closest Focus Distance: 6m advertised, 5m measured

Chassis Construction: Rubber-armoured aluminium

Prisms & Coatings: BaK4 prisms, fully multi-coated

ED Glass: No

Waterproof: Yes, IPX6 rating

Nitrogen Purged: Yes

Dioptric Compensation: +/-4

IPD Range: 53-74mm

Tripod Mountable: Yes

Dimensions: 17.5 x 19.8 x6.4cm

Weight: 925g advertised, 875g measured

Accessories: Padded neck strap, rubber rain guard and objective covers, instruction manual, soft padded case

Price: US $84.99

Ever since its founding in 2009, Svbony has been delighting the astronomy and sports optics community with an expanding range of high-quality products offered at very affordable prices. SVBONY is an acronym which stands for Saturn(S), Venus(V), Birding(B), Optics(O), Nature(N), Youth(Y). I was first introduced to the company a few short years ago when I stumbled on their excellent SV202 ED roof prism binoculars, which have since gone from strength to strength and are now being enjoyed by an army of nature enthusiasts the world over. Not long before this time, consumers were left with very little option to shell out significantly more money for products that often left a lot to be desired quality-wise. Be sure to check out the most recent reviews of these binoculars. Since discovering the SV202s, I have also enjoyed some of their excellent spotting scopes, and regularly use some of their high-quality zoom eyepieces, like the SV191, which I’ve begun to employ extensively this season to observe Jupiter.

As a dedicated fan of Porro prism binoculars, I’ve steadily come to realise their exceptional value for money owing to great advances in technology, as well as their much simpler design compared with high-performance roof prism binoculars. Truth be told, it takes a lot of knowledge and technology to create roof prism binoculars that can even begin to approach the quality of a traditional, well-made Porro prism design. What’s more, many of the conventional objections purists have laid against the humble Porro prism binocular have now been satisfactorily addressed, including advances in anti-refection coating technology, water- and fog-proofing, and the introduction of modern twist-up eyecups with much better eye relief to accommodate eye glass wearers. In addition, advances in material science also means that good Porro prism binoculars can now be manufactured with lower mass chassis, allowing them to be carried longer in the field.

It was these considerations, as well as my own experiences with several budget-priced Porro prism models that led me to appraise one of Svbony’s newest products, the SA204 10 x 50, a traditional Porro prism binocular. Having ordered several products directly from their online store, I decided to purchase this instrument directly from Svbony too, since they’re currently not available from Amazon UK.

First Impressions  

The SA204 10 x 50 package took about two weeks to arrive from the Far East to my home. As usual with Svbony, I was extremely impressed with the attention to detail in how it was packaged during its long trip to the UK. The instrument arrived double boxed inside some bubble wrap to ensure that nothing moved out of place during transit.  All the accessories were also neatly packed away, including the ocular and objective covers, a carrying strap, lens cleaning cloth, a well-written instruction manual and a decent soft padded carry case. Inspecting the binocular, my first impressions were very favourable. The instrument is covered in a high-quality textured rubber substrate, ribbed at the sides for extra grip. The twist-up eyecups moved smoothly and were easy to adjust, keeping their individual positions firmly when clicked into place. Two intermediate positions are available between fully retracted and fully extended, so plenty of options for those who like to experiment.

The aluminium central hinge is nicely tensioned, allowing you to easily adjust it to your preferred IPD. Once there, it stays rigidly in place. The rubber-covered central focus wheel has deep ridges to afford extra grip. Turning is very smooth with no free play. It ‘s quite stiff though, a consequence I suppose of the instrument being properly sealed and nitrogen purged. The focuser moves the eyepiece assembly up and down with no annoying wobbles I’ve seen in other instruments in this price class. 0.8 turns anticlockwise takes you from closest focus to jut beyond infinity. Eye relief is very generous. I was easily able to engage with the entire field using my varifocals, although I don’t wear spectacles when glassing under normal circumstances.

The dioptre adjustment is made using a small lever under the right eyepiece that rotates either clockwise or counter-clockwise, and I was easily able to find my optimal position. Once set in place, it stays there. I would say it’s very nicely engineered.

The large ocular lenses have nice green multi-coatings and the objectives are decently recessed as all good binoculars ought to be. The objective coatings appear to be significantly more subdued to those applied to the ocular eyepieces and I detected a faint reflection off one of the interior lenses possibly indicative of one surface being singly coated. The rain guard and tethered ocular covers are quite basic but do an adequate job protecting the lenes from rain and dust.

The instrument feels really nice in the hand with plenty of wiggle room to engage with my medium-sized mitts, making it easy to hold the instrument firmly. I was pleasantly surprised by the weight of the instrument without the strap and lens covers. Although the specs claim 925g, my SA204 tipped the scales at just 875g or 50 g less than advertised!  All in all, I came away with the impression that this was indeed a nicely appointed binocular, significantly better built than other 10 x 50 Porros I’ve tested in the past, including the Opticron Adventuer T WP and the Nikon Aculon.

Optics

My optical testing began by measuring the effective aperture of the instrument by directing my iPhone 11 torch into one of the eyepieces and measuring the size of the resulting circular shaft of light emerging on the other side of the objectives. By tracing a circle of diameter 50mm, I was able to show that the circular light shaft fitted snugly into the circle indicating that the SA204 was operating at its full aperture.

In the next test, I examined how well the binocular handled a beam of bright light. Turning on a sodium street lamp after dark, I was relieved to see that only a few minor internal reflections were seen that were largely non-injurious to the image. There was no diffused light around the light ether. Consulting my notebooks, I reported a little more internal reflections for both the Nikon Aculon and Action EX Porros(both of which retailing for considerably more than the SA204) I reviewed some time back and about the same as I recorded with two models of Opticron Adventurer T, but not quite as good as that seen in the significantly more expensive Opticron Imagic TGA WP(a £200 value).

Looking at the exit pupils yielded quite good results. I recorded nice round circles but I could see some light leaks around the pupils suggesting that better blackening on the inside of the tubes wouldn’t have gone astray.

I had the opportunity to test the SA204 in all kinds of lighting conditions. The image is quite good: sharp, nice contrast, with a surprisingly large sweet spot. Colour fringing is very well controlled, especially off-axis.In this capacity, it’s certainly in a completely different league to the Nikon Aculons I tested, which displayed alarming levels of lateral colour to my eyes. Glare suppression is quite good too. I discovered that by retracting the eyecups one notch down from fully extended improved both the visibility of the field stops and the amount of glare I recorded. The instrument has an impressively wide field of view of 6.5 degrees with very well-defined field stops. I did perceive some peripheral softness near the field edges but it was not at all objectionable to my eyes. The instrument does display strong pincushion distortion however. I took the liberty of photographing some pink flowers at a distance of about 30 yards to give the reader an idea of how well corrected the field is:

Close focus was measured at about 5m, less than the 6m advertised, putting it in the same ball park as a few other 10 x 50 Porro’s I’ve used. Of course, an instrument like this excels under the stars, where the 10x magnification and 50mm objectives pull in a lot of starlight. I checked collimation under the stars by defocusing the bright star Capella using the right eye dioptre while keeping the left barrel image as sharp as possible. The focused star remained well inside the defocused anulus not only in the centre of the field but also when placed to the extreme north, south, west and east edges, indicating very accurate alignment of the left and right barrels. Examining the Alpha Persei Cluster high up in the eastern sky reveals a rich cache of stars scattered across the field, I was delighted to see that they remained acceptably small and sharp across most of the field with only the outer 20 per cent of showing some mild distortion.  But even at the field stops bright stars like Vega and Altair remained quite tightly focused. Moving bright stars to the edge of the field showed little in the way of illumination drop off either. These results were most impressive for a large binocular retailing for significantly less than $100. Indeed, this instrument can be used to very good effect for general stargazing.

I estimated the field size by trying to image Alkaid and Mizar in the Plough, which have an angular separation of precisely 6 degrees 40’ or 6.66 angular degrees. I was unable to keep both stars in the same field of view but only just so, indicating that the advertised field size of 6.5 degrees was quite accurate. Views of the bright waning Moon rising over the eastern hills showed very nice results, with excellent crater detail coming through across the southern Highlands. There were a few minor internal reflections seen around the silvery orb, but they weren’t judged to be too offensive. I could detect a sliver of chromatic aberration at the edge of the Moon when centrally placed in the field  but this could be largely ameliorated by carefully reconfiguring eye placement. Off-axis colour fringing was more obvious though, but nothing I would describe as being out of the ordinary.

There was one negative however, and it manifested itself as I was imaging star fields in the vicinity of some streetlamps. Some of this peripheral light was entering the field, brightening the background sky by a tad. This disappeared however when I moved to the darkest location in my garden away from such light sources. In contrast, my Nikon E II 10 x 35(retailing at nearly ten times the price of the SA204) handled this stray light much more effectively. That said, I don’t count this as a major issue, and Svbony would do well to blacken the inside of the barrels that little bit more effectively.

Aperture Wins!

Lest anyone be uncertain about the benefits of aperture, I took the opportunity to test both the SA204 10 x 50 and Nikon E II 10 x 35 under a dark country sky with no Moon during the wee small hours of September 17. Turning the instruments on the faint galaxy duo M81 & M82 in Ursa Major, I did manage to see them in both instruments, but they were much easier to see in the 10 x 50. The same was true when I moved the instrument to the celebrated Double Cluster in Perseus, now passing near the zenith at about 2.00 am local time. The view was compelling in both instruments, but the clusters were considerably richer in the larger glass. Ditto for the wondrous Pleiades and Hyades in Taurus as well as tracking down the trio of Messier open clusters in Auriga still low in the east. Indeed, I was quite impressed by just how well the SA204 managed to image the Hyades, with its constituent stars filling most of the field. I noted how well defined fiery red Aldebaran presented itself when positioned at the south-eastern edge of the field! All this to show that ‘you cannae change the laws o’ physics captain’ no matter how sexy and optically pristine the smaller, more expensive glass may be.

Conclusions and Recommendations

The Svbony SA204 10 x 50 represents excellent bang for buck. It serves up a well corrected, sharp, bright and high contrast image with good control of chromatic aberration. It will serve as a fine general-purpose binocular, where it excels at low light observations and astronomy. I would have been thoroughly delighted with an instrument like this were I starting out in binocular astronomy again. I would however recommend using a more substantial neck strap than the generic one supplied with a chunky instrument like this. Better attention to internal blackening to improve contrast when observing under bright night lighting would also go a long way to making it an even better performer. That said, if you’re after a cost-effective instrument that does many things well, I would certainly recommend this neat 10 x 50 Porro to all and sundry.

Dr Neil English’s new 650+ page book, Choosing and Using Binoculars: A Guide for Stargazers, Birders and Outdoor Enthusiasts, caters for all budgets and will soon be published in paperback. Now available for pre-order.  

De Fideli.

A Work Commenced July 7 2021

 

Preamble

 

Product: Ricoh-Pentax SP 10 x 50 WP 

Country of Manufacture: China

Field of View: 87m@1000m( 5 angular degrees)

Eye Relief: 20mm

Close Focus: 5.5m

Exit Pupil: 5mm

Focuser: Central, lockable

Chassis Material: Aluminium with rubberised overcoat

Coatings: Fully broadband multi-coated throughout

Dioptre Range: +/- 4 dioptres

Nitrogen Purged: Yes

Waterproof: Yes (JIS Class 6)

ED Glass: No

Weight: 1060g

Dimensions: 18 x 18 cm

Retail Price: £170UK

Supplied with: Soft carry case, logoed carry strap, plastic objective and ocular covers, multi-language instruction sheet.

 

Pentax is a company long synonymous with good optical quality. Over the last few years, I’ve reviewed a few models manufactured by this company, ranging from the very small(6.5x 21) to the very large(20x 60). In particular, I’ve included an earlier incarnation of the  20 x 60 SP model in my own personal arsenal of binoculars, where it’s employed in deep sky observation and regular white light solar observing. So, I was excited to see how its smaller sibling, the 10x 50 SP WP, would shape up in field tests.

First Impressions

I purchased the binocular with my own money and it set me back £170, inclusive of delivery charges. The binocular arrived double boxed, including the instrument itself, packed inside its soft case, together with plastic end caps for both the ocular and objective lenses, a logoed padded next strap and instruction sheet containing information concerning the warranty. The plastic caps that protect the optics of the 10 x 50 SP looked identical to those that accompanied my 20 x 60, and together with the woefully inadequate soft case, represent the weakest links in the entire package. The caps are loosely fitting and invariably fall off  when the binocular is picked up. As for the case, it does very little to protect the binocular from serious knocks so should really be upgraded to either a padded soft case or better still, an aluminium hard case to protect your investment.

Ergonomics

Thankfully, my initial impressions of the binocular itself were far more favourable. When I unpacked it, I was immediately struck by its rugged build quality. The binocular weighs in at a hefty 1kg and is covered with a thick layer of synthetic rubber identical to that found on my 20 x 60 . Like its bigger brother, it has a lockable focuser; simply push the wheel forward and it disengages with the internal gearing, preventing the wheel from being moved. Although not an essential feature by any means, I can see where it would come in useful if one observes targets at a fixed distance from the user or when observing the night sky, where all the subjects are located more or less at infinity.

The twist up eyecups are very well made and very comfortable to use. There are three positions; fully down, intermediate and fully extended. Eye relief is a very generous 20mm. Usually, I observe with the eye cups fully extended but I actually found the view to be most comfortable and immersive at the intermediate position without wearing eye glasses.

The ‘WP’ part of its name, I assume, refers to ‘Water Proof,’ with a specified JIS class 6 rating. The instrument is purged with dry nitrogen gas to prevent internal fogging and is O-ring sealed. The dioptre ring is located under the right ocular lens and is negotiated by moving an easy to access lever which can be adjusted clockwise or anti-clockwise. It is reasonably stiff to the touch so should hold its position well. The underside of the 10x 50 SP WP has two large thumb indents for easier hand holding. I found that my thumbs naturally rested in them while holding the binocular up to my eyes.

The focus wheel is very stiff; a strict no-no for birding or any activity that requires rapid focus changes. But for stargazing or for stationary targets located in the distance, it works just fine.

Optics

The proof of the pudding, of course, lies in the eating, and this is where this well-made classic Porro prism binocular really shines. The SP series underwent an upgrade from the first generation models, with better multi-layer anti-reflection coatings being applied throughout the optical train. Allbinos tested this model out and measured a light transmission value of about 85%, which is very good indeed considering the modest price tag on this binocular, as well as the fact that some of the world’s best Porro prism binos achieve about 95% or so.

Not for the Birds

Inspecting the innards of the instrument in broad daylight showed it to be clean and dust free. Setting up my iphone torch to its highest setting in my back garden at dusk and placing it a comfortable distance away revealed a few minor internal reflections and no diffraction spikes or diffused areas; another good result indicating that all was well with the instrument in keeping bright light sources under control. Placing the beam just outside the field of view showed very little ghosting so this will be a good binocular to observe bright objects in the night sky such as the full Moon and stars located near it. It will also garner excellent views of cityscapes at night. Close focus was measured to be about 5.3 metres – a little better than advertised but nothing to write home about. The coatings on the ocular and objective lenses seem to be very evenly applied. In addition, the objective lenses are very deeply recessed which helps protect the optics from the vagaries of the British climate and also cuts down on stray light.

In broad daylight, the view through the Pentax 10x 50 SP WP is very impressive, with great contrast, good colour rendition and good but not outstanding control of glare. Depth of focus is not bad, but the 3D pop that Porro prism binoculars are famous for was there in spades. Colour correction is excellent, even off axis, where one can detect a small amount of lateral colour. Field curvature is very gentle but does show a fairly minimal amount of pincushion distortion near the field stops. Even though the field of view is fairly narrow at 5 angular degrees, it didn’t feel overly restrictive to my eyes. At just over 1kg weight and delivering a 10x optical boost, these are not binoculars that one could handhold for long but it’s certainly possible to scan the landscape and night sky for a few minutes before some fatigue sets in. These are however, perfect for use on a lightweight monopod or tripod for ultra stable viewing.

Further testing at dusk showed excellent control of internal reflections and clean, crisp images garnered from a bright sodium street lamp. Placing the lamp just outside the field of view showed up no significant off-axis flares. Placing the binocular on a light weight monopod and turning them on the night sky also served up excellent results. Centring the bright Summer luminary, Vega, in the binocular field and focusing in showed a pinpoint sharp image with no secondary spectrum and with no diffraction spikes. Better still, moving the star to the edge of the field induced only a little distortion and some lateral colour(purple fringing), indicating that the aspherical optical element built into the eyepieces of the Pentax SP binocular were doing their jobs well. And while the skies were far too bright to provide a more in-depth study, with strong Summer twilight upon us here in central Scotland,  I compared and contrasted the view through the Pentax 10 x 50 and my trusty Barr & Stroud Series 5 8 x 42 mounted on a second monopod. Turning my attention to the well placed Coathanger asterism in Vulpecula revealed a cleanly resolved view in both instruments, but with fainter stars showing up better in the Pentax, albeit in a smaller true field.

Conclusions & Recommendations

In recent years, thanks to great advances in technology, there has been a steady movement within the amateur community towards roof prism designs over older, Porro prism binoculars. But after spending a few weeks testing out this affordable model from Pentax, I was genuinely surprised and delighted by its optical performance. Indeed, you’d have to fork much more money for a roof prism binocular with the same specifications as this Pentax to get the same optical quality. The only real advantage of the roof prism incarnations at 10 x 50 are their lower mass(but not by much) and slightly smaller frames. Having sampled a few inexpensive and mid-priced 10 x 50 roof prism binoculars in the past, I can say hand on heart, that they did not deliver the light transmission values anywhere near those attained by this classic, affordable 10 x 50. Indeed, I would strongly recommend readers to look more closely at tried and trusted Porro prism designs in aperture classes of 50mm or above over the roof prism varieties, especially now that they come with full waterproofing.

Qui bono?

Amateur astronomers looking for quality deep sky views on dark, clear nights, and casual daytime viewers with permanently set-up tripods or monopods surveying targets set in the distance. Remember that five degrees is still plenty good enough for the vast majority of deep sky observing! These would work very well in holiday cottages set by a lake or overlooking a picturesque valley floor. And although they can be handheld for short excursions, they do benefit greatly from mounting.

Very highly recommended!

 

 

 

Dr Neil English has over 40 years experience studying the night sky with all sorts of telescopes, but in the last few years has devoted himself to seeking out bargains for savvy binocular enthusiasts. His highly lauded 650+ page magnum opus, Chronicling the Golden Age of Astronomy, summarises four centuries of telescopic observing, from Thomas Harriot to Patrick Moore.

 

 

De Fideli.