A Work Commenced March 20 2021
Product: Opticron Adventurer 8 x 32 T WP
Country of Manufacture: China
Chassis Material: Rubberised Aluminium & Polycarbonate
Exit Pupil: 4mm
Field of View: 142m@1000m(8.1 angular degrees)
Coatings: Fully Multicoated on all glass surfaces
Prisms: Porro BAK4
ED Glass: No
Close Focus: 3m advertised, 3.24m measured
Dioptre Compensation: +/- 5
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: 540g measured
Warranty: 2 Years
Dimensions LxWxD (cm): 10.9 x 16.9 x 5.0
Every now and then, a product finds its way to me, challenging what I know and understand about binoculars, and their market. As you may have gathered, I have spent the vast majority of my reviews on modern roof prism designs, which are understandably very popular with nature enthusiasts, birders and hunters alike. The advantages of roof prism models include their compact, sleek design, internal focusing and ease with which they can be rendered weather resistant. But for all their charms, roof prisms are much more difficult to make well compared with the older, more traditional, porro-prism designs. For one thing, they need specialised phase corrections coatings that bring the electric field vectors into precise alignment after being shifted out of phase, travelling through the roof prism. They also require aluminised, silvered or dielectric coatings to boost the light transmission to the eye to achieve their high-contrast images, that can begin to compete with their porro-prism counterparts. But while the market has clearly moved in favour of roof prism designs, it’s good to see that some of the leading binocular manufacturing companies have retained one or more porro-prism models that offer wonderful optical performance in classic configurations. I speak of course of the Swarovski Habicht, for example, which is still available in 30mm and 42mm formats, and offer exceptional optical performance at prices substantially below their equivalent roof prism counterparts.
Zeiss also continued their manufacturing of classic porro-prism designs, like the multicoated Jenoptem 8 x 30, well into the 1990s, and the later models still provide excellent optical performance. Nikon also makes its highly-lauded EII as a premium product, as well as a number of less expensive porro-prism models – the Aculons & Actions come to mind- that deliver decent optical performance, apparently. But it’s also nice to see other binocular companies like Opticron, Vortex, Kowa, Olympus, Canon and Leupold continue to offer small porro-prism binoculars at very economical prices.
Truth be told, with vast improvements in optical glass quality, modern multi-coating technology, and advancements in materials science, it’s possible to produce an optically excellent porro-prism binocular for a very modest financial outlay. This review will describe the optical and mechanical features of a charming little porro-prism binocular by Opticron; the Adventurer 8 x 32 T WP.
Inspiration from Fellow Astronomy Authors
My attention to the Opticron Adventurer T WP 8 x 32 was piqued after reading some reviews made by British binocular astronomer, Stephen Tonkin, who showcased a very interesting Adventurer T WP 10 x 50 model, and highly recommended this model as a well-built and optically excellent stargazing binocular available for under £100. Indeed, this was also reflected in the many favourable reviews left by stargazers about the same model. But there was almost nothing mentioned about the smaller models from the same line; namely the 42mm and 32mm models. I discovered that 32mm Adventure T WP had a nice, light weight- 540g – quite typical even for a roof prism model of the same aperture class. It offered a good, wide field of view too – 143m at 1000m – again right up there with some of the widest fields available in the top-selling roof prism brands. But unlike many older models, which offered just coated or multi-coated optics, these porro-prism binos from Opticron were fully mutli-coated, ensuring a high light transmission – at least in theory.
I decided to order up the Opticron from Amazon, which was offering the instrument for a very attractive price of just £61. This was a little bit below what I would have expected it to sell for, so I suspected that I was going to get the binocular in an ‘open box’ condition, meaning that some previous customer opened up the package, briefly examined the instrument, before packing it away and sending it back to Amazon. Sure enough, when the package arrived, it certainly looked like the box was opened before!
Everything looked OK though. The binocular itself was very nicely built – much better, in fact, than I had expected, if I’m being honest. My initial impression was, ” this has got to be a Habicht clone,” so similar it appeared to the famous Swarovski classic.
Holding it in my hands, I was very satisfied with its sturdy build. The central hinge is good and stiff, easily maintaining my preferred inter-pupillary-distance. The focus wheel is very nicely engineered, rotating smoothly with a fair amount of tension and without any play or backlash. The eye cups are the old-school rubber design but they felt quite comfortable to rest my eyes on. When folded down, the instrument can be used with eye glasses, but you’ll have to move your eyeball ’round to see it all, so a fairly tight squeeze! Dioptre compensation is achieved by rotating a ring located under the right ocular. It also moves smoothly but I would have liked to see that little bit more tension.
I hit my one and only snag as I began to remove the nicely designed objective covers from the barrels. The rubberised armouring immediately covering the left ocular came away, as I struggled to tease the objective cover off.
Fortunately though, I had some Gorilla glue handy, and simply applied a bit to the inside of the armouring before putting it back on. It worked a treat, but it did leave a few glue streaks around the rim, lol, as you can see in the photo below:
The objectives are quite deeply recessed, with the anti-reflection coatings almost disappearing in normal daylight. That’s a good design feature, as it affords greater protection from dust, rain and stray light.
I was delighted to see that Opticron made a provision for affixing the binocular to a tripod. Good move!
The binocular handles very well indeed. It’s super easy to grip and wrap one’s fingers ’round. The focus wheel is easily accessed and moves with a very reassuring amount of tension. Fit and feel are way better than I expected, given its rock-bottom price. But how did the optics hold up?
I had read that more economically priced porro-prism binos, like this 8 x 32, often have stopped down apertures. This was very easy to test however, simply by directing my Iphone torch through the ocular lens and observing the size of the circle of light projected through the objectives onto a flat surface. The results were very encouraging: the effective diameter was 31mm, quite in keeping with the 32mm advertised aperture.
Next, I turned my phone torch to its highest setting and placed it about 4 metres away at the other end of my living room. Looking at the beam through the binocular produced yet another excellent result; there were no significant internal reflections or diffraction spikes. I did detect a small amount of diffused light around the beam, though I judged it largely un-injurious to the image. This I was able to confirm by imaging a sodium street lamp at night. There was no annoying internal reflections and just a small amount of diffused light immediately around the lamp. All in all, these results were thrilling, given the very low price I paid for this binocular!
In the next test, I photographed the entrance pupils on both the left and right ocular lenses. As you can see, the pupils were round, with no sign of truncation. Nor did they display the characteristic signs of cheaper BK7 prisms. I did detect some light leaks away from the entrance pupils however, but all in, not too shabby!
The Opticron Adventurer 8 x 32 T WP delivers a very good image in daylight tests. The sweet spot is generously large. Contrast and colour rendering were both excellent. Images snap to precise focus, with the focus wheel moving through about one and a half full rotations from nearest focus(measured at 3.24m) to infinity. What immediately impressed me most was the instrument’s extraordinary depth of focus, with objects in the middle distance and beyond taking on a wonderful, immersive three-dimensionality. This amazing effect is far more acutely perceived in this binocular than in any roof prism instrument I’ve had the privilege of using. Of course, porro-prism binoculars are known for this, but it still came as quite a surprise to me when scanning a stretch of river, an open field, or a woody glade. The viewing is extremely comfortable too. I encountered no blackouts or rolling ball effects while panning large swathes of wooded terrain.
The binocular does suffer a little bit from glare, especially when it’s pointed near the Sun, but no more than many other binoculars I’ve tested costing many times more. In most situations, this glare can be minimised simply by outstretching one’s hand.
I noted very little chromatic effects within the sweet spot, but did begin to see traces as my eyes were directed towards the edges of the field. The periphery of the field becomes progressively more blurry, but the decline in image sharpness is very gentle and gradual. The main off-axis aberration is field curvature. I took the liberty of capturing an image of a nearby roof through the Opticron and compared it to the same image captured by a GPO 8 x 32 Passion ED costing more than six times more. I hope you’ll agree that compared with the GPO binocular, the little Opticron Adventurer T did very well indeed, both on and off axis.
Though the captured IPhone images don’t fully convey the visual impressions garnered with the eye-brain interlocutor, they do show that the GPO delivers a punchier, more contrasted image. That said, the little Adventurer did very well indeed. The reader will also note the greater focus depth of the Adventurer T (see the tree in the background at the top of both images) as well as a little bit of vignetting at the edge of the field. Since the fields are broadly the same size, one can see field curvature is pretty similar in both instruments i.e. gentle.
While it was pretty clear from the get go that the Opticron Adventurer T was well collimated, as evidenced by the wonderful depth perception I experienced after merging the images, I did confirm this by testing on a bright star at night and it passed. Looking at a decidedly pinkish full Moon rising low in the eastern sky, the image was bright and sharp across the majority of the field. As the Moon was moved off axis toward the field stop, I did notice a significant brightness drop off at the edges, in keeping with the results seen in the image captured above.
Star fields were presented really well in the Opticron too, with stars remaining acceptably small and sharp across most of the field. Like many other binoculars I’ve showcased in the past, off axis aberrations are more pronounced panning the instrument vertically than horizontally. This will make a very decent stargazing bino for those who like to use smaller instruments.
To say that I’m impressed with this little binocular would be quite an understatement. For the ridiculously low price I paid for it, the Opticron Adventurer 8 x 32 T WP performed WAY ABOVE expectations. It may be an inexpensive binocular, but boy does it perform! It’s lovely wide field, sharp optics and wonderful depth of focus will allure many. And while it’s no Habicht, it gets my highest recommendation as arguably one of the most charming instruments I’ve had the pleasure of reviewing.
Long live the classic porro prism binocular!
Thanks for reading!